- RAM是易失的，所以他需要供电
- The software you install（安装） to help a printer communicate with a computer is called a device driver.
- Serial processing is when a processor begins executing（执行） one instruction before it completes the previous instruction.
- Public key encryption uses a public key to encrypt messages, but a private key is required to decrypt messages.
- A computer’s operating system is not a type of application software.
- The list of codes for a microprocessor’s instruction set is called machine language.
- A compiler converts source code to object code.
- A dictionary attack is a virus that hides out in the spelling checker for your word processing software.
- Today’s computers typically process 32 or 64 bits at a time.
- In RAM microscopic（微型的） electronic parts called capacitors（电容器） hold the bits that represent datA.
- ROM is a type of memory that holds the6 computer’s startup routine.
- Hard disk drives, optical drives, and solid state drives are not random access devices.
- CD-RWs doesn't allow you to record data, but data cannot be changed once it is recorded
- The most popular type of wired connection is Ethernet.
- The Domain Name System stores IP addresses and their equivalent domain names
- Dial-up and DSL provide Internet access using telephone cabling.
- The Web uses cookies because HTTP is stateless.
- E-mail attachments are converted with MIME into ASCII code.
- Any access to data or programs by hackers, criminals, or other unauthorized persons is called intrusion.
- Ethernet simultaneously broadcasts data packets to all network devices.
- A B2C e-commerce transaction occurs when individual consumers purchase goods and services from online merchants.
-
The type of code that uses only seven bits for each character is ASCII
The Extended ASCII uses 8bits
-
If virus protection software identifies a virus, it can try to take all of the following actions including remove the infection,delete the file,put the file in quarantine,but except shut down the computer
-
A submenu,menu selection or dialog box is an additional set of commands that the computer displays after you make a selection from the main menu.
-
The main directory maintained by your computer’s operating system is the root directory (based on Linux/Unix)
-
Application software is designed to accomplish real-world tasks.
-
RAM is a temporary holding area for data, application program instructions, and the operating system.
-
RAM can be thought of as the waiting room for the computer’s processor
-
A connecting link is a physical path or a frequency used for signal transmissions.
-
A hard disk platter is a flat, rigid disk made of aluminum or glass and coated with magnetic iron oxide particles.
-
Antispyware software is a type of security software designed to identify and neutralize Web bugs, ad-serving cookies, and other types of malware.
-
A(n) web is a collection of related information organized and formatted so it can be accessed using software called a browser
-
To find a particular record or group of records in a database, you use a query.
-
A group of sectors is called a cluster.
-
Cable currently offers the fastest Internet access speeds.
-
Cable Internet service needs circuitry to handle Ethernet protocols and a cable modem.
-
Portable Internet access includes all of the following EXCEPT WIFI
-
A compute-intensive problem runs on a supercomputer
- solid state storage
- magnetic storage
- bubble storage
- optical storage
Consider PC as a part of the information system.
- The PCs are making people, end users like you,more productive.
- Privacy
- Environment
- Ethics
- Careers in IT
-
The rules or guidelines for people to follow when using software,harware,data are procedures.
-
They are usually documented in manuals
- Tell the computer how to do its work.
- Anothe name for a program
- Convert data(umprocessed facts) into Information(processed facts).
- Enables the application software to interact with the computer hardware
- a collection of programs
- Operating System（操作系统）:smartphones use embedded operating system,also known as real-time operating systems(RTOS);desktop computers use standalone operating systems;networks use network operating system.
- Utilities:An example,antivirus program.
-
General-purpose applications（通用应用程序）
To be considered an efficient and effective end user.
- Word processors
- Spreadsheets:Analyze and summarize numerical data.
- Database management systems（数据库管理系统）
- Presentation software:Communicate a message or persuade other people.
-
Specialized applications
More narrowly focused on specific disciplines and occupations
- Graphics（图像处理）
- Web authoring programs
-
Mobile apps
Primiraly designed for mobile device.
- Social networking
- Games
- Downloading music and videos
- The equipment that processes the data to create information.
- Includes smartphones, tablet,keyboards,mice,displays,system units,and other devices.
- Controlled by software.
- Supercomputers（超算）:most powerful;analyze and predict worldwide weather patterns;for example,IBM's Blur Gene
- Mainframe computers（大型机）:for example,insurance companies use them to process information about millions of policyholders.
- Midrange computers（中型机）:support or serve end users for such specific needs as retrieving data from a database or supplying access to application software.
- Personal computers(PCs):five types
- Desktop computers
- Laptop computers(notebook computers)
- Tablets(Tablet computers)
- Smartphones
- Wearable device
Cell phone is also a computer
-
System unit(Chapter5)（系统单元）:a contaniner thar houses most of the electronic components that make up a computer system;microprocessors and memory are two important components
One type of memory is random-access memory(RAM) which is sometimes referred to as temporary storage
此概念是指计算机的硬件组成
-
Input/output(Chapter6):keyboard and mouse; display,as known monitor
-
Secondary storage(Chapter7)(外存):holds data constantly
Hard disks:using rigid metallic platters and read/write heas that move across the platters,data and information are stored using magnetic charges on diks's surface.
Solid-state storage:save data similar to RAMs
Optical discs:using laser tchnology to store data and programs; including compact discs(CDs),digital versatile(or video) discs(DvD),and Blu-ray Discs(BD)
-
Communication(Chapter8)
-
The raw information
与information相对，data是指未经处理的元数据
- Document files
- Worksheet files
- Database files
- Presentation files
- A way to connect to other people and computers.
¶ Connectivity and the Mobile Internet
- A network is a communications system connecting two or more computers
- The largest network in the world is the Internet
- The web provides a multimedia interface to the resource
- Cloud computing(云计算)
- Wireless communication
- Internet of Things(物联网)
¶ Chapter2 The Internet,The WEB ,and Electronic Commerce
¶ The Internet and the Web
- Adavanced Research Project Agency Network(ARPANET), an immense network that connects small er networks was launched in 1969
- The web, also known as the World Wide Web or WWW, was introduced in 1991.
- The web made a multimedia interface to resources on ther internet.
- Web1.0: linking existing information
- Google and other research engines made it possible to search web pages
- Many users can view web content, but few can create web content
- Web2.0:more dynamic content creation and social interaction
- Facebook and othe social media are examples
- Web3.0:identifies relations between data
- Siri and Google Assistant are exmples
- Web4.0:connect data and devices into a seamless integration into our physical life
¶ Web and Internet
-
The Internet is a physical network, which is made up of wires, cables,satallites, and rules for exchanging information between computers connected to the network.
-
Being connected to the web is called online.
-
The web is a multimedia interface.
区分internet和web的根本差异就是internet是一个物理层面的网络，web是对internet这个物理网络的封装。在web出现之前，对internet的使用就像是GUI出现之前使用DOS
- Communicating
- Shopping
- Searching
- Education or e-learning
- Online entertainment
- TV Shows and Movies
- Online Music
- Online Book
- Social Media
- News feeds
-
The most common way to connect to the Internet is through an Internet service provider(ISP)(网络服务提供商)
-
Using telephone lines cable, and/or wireless connections
该条目是指连接的物理方式
-
Providers in America includs AT&T, Comcast,Sprint,T-Mobile, and Verizon
-
Connection techonologies including DSL, cable, and wireless modem
该条目是指连接的技术
-
The progrm to connect to theInterne is called the browsers
-
Apple Safari,Google Chrome,FireFox,Microsoft Egde,etc
-
The location or address of the resource is called uniform resource locators(URLs)(统一资源定位符)
URL：统一资源定位符
URI(uniform resource identiter)：统一资源识别符
-
All URLs have at least two basic parts
-
To present the protocol(协议). http/https is used for web traffic
-
To present the domain name(域名). The last part of the domain name following the dot is the top-level domain(TLD)（顶级域名）,also known as the web suffix,which identifies thetype of the organization.
| Domain |
Type |
| .com |
Commercial |
| .edu |
Educational |
| .gov |
Goverment |
| .mil |
U.S.military |
| .net |
Network |
| .org |
Organization |
-
An document will be sent back once connected to the website, which usually contains Hypertext Markup Language(HTML)(超文本标记语言),a language displaying web page.
-
Many techonologies are used to show animated and interactive websites
-
JavaScript:used within HTML to trigger interactive features, executes on the user's computer
-
PHP:executes on the website's computer
-
Cascading style sheets(CSS):control the appearence of the web page
JavaScript是一种运行在浏览器上的脚本语言，往往被用在客户端；PHP往往被用于服务端开发
- block access to selected sites
-
Web-based file transfer services:make use of a browser to upload and download files,such as dropbox.com
-
BitTorrent(种子): distributes a file across many computers to accelerate.
A single file might be located on dozens of individual computers.
Have been used for distributing unauthorized copies of copyrighted music and video
-
FIle transfer pritocol(FTP) and secure FTP(SFTP)
- Designed to maintain the security and privacy
-
Profiles:created by users to share information about them
-
Pages:created by companies to promote their bussiness
-
Groups:communities of individuals
-
Friends
-
News feed:the first page you see after you log in.
consists of a collection of recent posts
-
Share settings
¶ Blogs,MicroBlogs,podcasts,and Wikis
- Personal websites is called blogs
- Microblogs are designed to use with mobile devices,such as Twitter and Instagram
- wiki is a website designed to allow visitors to add, edit,or delete the content
- Text Massaging,or short message service(SMS):typically fewer than 160 characters
- Multimedia message servie(MMS):a SMS with images, video or sound
- Instant message(IM)
A typical e-mail message has four basic parts:header, message,signature and newsletters
Header appears first and includes
- Address:username@domain name
- Subject:A one-line description
You can add attachments in an e-mail
Two basic types of e-mail systems
- Client-based e-mail system:Run **a program to communicate with ther e-mail service provider,**such as Apple's Mail and Microsofts' Outlook
- Web-based e-mail system:Once the web browser connected to the e-mail service provider, a webmail client is run on the provider's computer ,known as the webmail.
Webmail is userd more widely because if frees the user
The unwelcomed e-mail is called spam
- Special Programs called spiderscontinually look fornew information and update the search service's database
- Authority
- Accuracy
- Objectivity
- Currency
- Bussiness-to-consumer(B2C)
- Consumer-to-consumer(C2C):such as web auctions,ebay.com
- Business-to-Bussiness(B2B)
Basic components
- Clients
- The internet
- The service provider
- Graphic user interface (GUI)(图形用户界面) displays graphical elements called icons to represent familiar objects.
- The standard GUI includes
- Menus:on the top of a window,displays in a menu bar
- Toolbars:appear below the menu bar and include small graphical elements called buttons
- Dialog boxes:additioanl information and request user input
- Many applications use an iterface known as the Ribbon GUI, which changes based on the need of the user
- Ribbons:replace toolbars and menus by re-combining them together,displayed at tabs and appear in the first ribbon
- Tabs:divide the ribbon into major activity areas.Then organized into groups containg related items. Some taabs called contextual tabs appear only when they are needed
- Galleries:provide additional options and simplify choosing and option by showing the effect
- Spell checker
- Alignment-centers
- Fonts and font sizings
- Character effects
- Edit options: provide easy ways to edit text, such as cut, copy and paste
- Find and Replace
- Grmmar chacker
- Autocorrect
- Captions:Identifying figures with captions in areport makes the report easier to read and more professional
- Footnote
- Header ot Footer
- Workssheets
- Functions
- Cells
- Formulas
- Workbook
- Templates:provide an easy way to create a presentation by providing pre-designed styles and layouts
- Animation
- Document Theme
- Primary Key:the unique identification key
- Record:A combination of data
- Fields:are given names that are displayed at the top of each table
-
Video editors
-
Image Editor, also known as photo editor
A picture consists of thousands of dots, or pixels(像素) is referred as bitmap(位图) or raster images.
-
Illustration programs, also known as drawing programs:to create and edit vector(矢量图) images
-
Desktop Publishing programs
¶ Specialized and Utility Suites
Four types
- Operating system
- Utilities: perform specific taks related to computer's resources
- Device Drivers（设备驱动）
- Language translators(编译器): convert the programming instructions written by programmers into a language that computers understand and process
The most important type of computer programs
Often referred to as the software environment or software platform
- Managing resource:coordinate computer's resource including memory, processing. storage and devices; monitor system performance, schedule taks, etc
- Providing user interface
- Running applications: most support multitasking or the ability to switch between different applications stored in the memory; the application you're running is in the foreground, the others are in the background
- Starting or restarting a computer is called booting the system.
- Booting has two ways: a warm boot and a cold boot
- A warm boot is when the computer is running and you restart it without cutting the power off
- A cold boot means start a computer that has been turned off
- Most OSs provide a desktop to access the computer resource
- Icons: a graphical representation of a application, a file or function
- Pointer
- Windows
- Menus: a list of options or commands
- Tabs: devide menus into major activity areas such as format and page layout
- Dialog Boxes
- Help:provide online assistance
- Gesture control: ability to control operation with finger movements, such as swiping, sliding and pinching
- Embedded operating systems, also real-time operating systems(RTOS):small electronic devices such as smartphones and smartwatches.
- Stand-alone operating systems,also known as desktop operating systems: control a single desktop or laptop computer
- Netork operating systems: used to control and coordinate computers that are networked or linked together; thet're typically located on one of the connected computers' hard disks. the computer is called network server.
Less complicateed and more specialized for wireless communications
- Android: developed by Google based on the Linux
- iOS
¶ UNIX and Linux
- Linux is an operating system that extended onr of the UNIX versions
- Chrome OS is based on Linux
- A single computer can support multiple operating systems that operate independently
- The virtual computers are called virtual machines
- The OS of the physical machine is called host operating system, and of the virtual machines are called guest operating systems
- Search programs
- Storage management programs
- Backup programs
- Antivirus programs
- Troubleshooting or diagnostic programs
- Virtual assistance
- Search programs
- Storage management program: identify and remove unused files and applications
- Backup programe
- System unit, also known as system chassis is a container of electronic components
- Two-in-one laptops
- Gaming laptops
- Ultrabooks/ultraportables/mini notebooks
- All-in-one desktops
- Tower unit or tower computer
- Smartwatches
- Activity trackers
-
Also known as the mainboard or the mother board
-
For mobile devices, the system board is located behind the screen; and for laptops and desktops is located at the bottom of the system unit or along one side
-
It's a flat circuit board covered with components, like:
-
Sockets: a connection point for small specialized electronice parts called chips
Chips consist of tiny circuit boards etched onto squares of sandlike material called silicon
A chip is also called a silicon chip,semicondeuctor, or integrated circuit
Chips are mounted onto chip carriers, and the carriers can be plugged into slots on the system board
-
Slots: a connection point for specialized cards or circuit boards
-
Bus lines,also known as connecting lines: provide pathways for communicating
Mostly, the central processing unit(CPU) or processor is contained on a single chip cakked the microprocessor
- Control unit: directs the movements of electronic signals between memory
- Arithmetic-logic unit(ALU): Artithmetic operations includes: addition, subtraction, multiplication, and division;Logical operations consists equal, less than and greater than
- Chip processing capacity are expressed in word sizes such as 32/64bits
- The processing speed is represented by its clock speed
- Many computers have multicore processors that can provide two or more sparate and independent CPUs
- Parallel processing is a method to divide tasks into each CPU
- Coprocessors are special chips to improve specific computing operations
- Graphic coprocessors, also known as a GPU(graphics processing uni)
¶ RAM(Random-access memory)
- RAM is called temporary or volatile storage because ecerything in the RAM is lost once the power is cut off
- Cache memory acts as a temporary high-speed holding area between memory and the PCU
- DIMM(dual in-line memory module) can be inserted into the system board to expand the RAM
- Virtual memory is able to work as a RAM to run large programs
- It's not volatile and can't be changed by the user
- only CPU can read , or retrieve, data and programs written on the ROM chip
- used to store the start-up instructions, which is called the system's BIOS(basic input/output system).
¶ Expansion Cards and Slots
- Graphics cards
- Network interface cards(NIC),also known as network adapter cards
- Wireless network cards
- The number of bits that can travel simultaneously down a bus is known as the bus width
- System buses connects the CPU to memory and expansion buses connects CPU to other components on the system board, including expansion slots
- Universal Serial Bus(USB):the current USB standard is USB 3.2
- FireWire buses: used to connect video and audio devices
- PCI express(PCIe): provide a singele dedicated path for each connected device
¶ Standdard Ports
- Universal serial bus ports:USB-A,B,C;a single SUB port can connect to many USB devices
- HIgh Definition Multimedia Interface(HDMI) port
- Thunderbolt ports
- Ethernet ports
- Mini DisplayPort
- VGA(Video Graphics Adapter) and DVI(Digital Video Interface)
- FireWire ports
Computers require direcet current(DC)
- DC adpter can convert AC to DC and charge the battery
- Wireless charging platform can chage without cable
- Power supply unit is working in a desktop
¶ Electronic Data and Instructions
- Decimal, binary and Hexadecimal system
- In the history, pC uses ASCII(America Standard Code for Information Interchange), the Mainframe uses EBCDIC(Extended Binary CodedDecimal Interchange Code)
- Unicode
- Virtual keyboards
- Laptop keyboards
- Traditional keyboards: toggle keys and combination keys
- A stylus is a penlike device which works with the handwriting recognition software
- Writing recognition software translates handwritten notes into a form that the system unit can process
- Multitouch screens can be touched with one or ore fingers
- Joysticks
- Gaming mice
- Gamepads
- Motion-sensing devices
- Flatbed scanner: like a copy machine
- Document scanner: quickly scan multipage document
- Portable scanner
- 3D scanner
- Read the encoded information stored in the card
- UPC(Universal Product Codes): automate the process to check oult customers, change product prices and to maintain inventory records
- MaxiCode
¶ Character and Mark Recognition Device
- Magnetic-ink character recognition(MICR)
- Optical-character recognition(OCR)
- Optical-mark recognition(OMR): often used to score standardized multiple-choice tests
Clarity refers to the quality and sharpness of the displayed images
- Resolution
- Dot(pixel) pitch: the distance between each pixel; Cell phones can have smaller pitches
- Contrast ratios
- Active display area
- Aspect ratio
- LCD(liquid crystal display): used for older monitors and less expensive
- LED(light-emitting diode)
- OLED(organic light-emitting diode)
- E-ink, used by E-book readers, produces images that reflect light like ordinary paper
- Digital or interactive monitors
- Flexible screens
- DIgital projectors
- Resolution: meaured in dpi(dots per inch), the higher the better
- Color capability: grayscale, images are displayed using many shades of gray
- Speed
- Memory: to store printing instructions and documents
- Duplex printing: printing in both sides of a sheet of paper
- Connectivity: the ability to connect to the network
- Cloud printer
- Thermal printer: use heat elements to produce image on heat-sensitive paper
- Plotter
¶ Virtual Reality Head-Mounted Displays and Controllers
- RAM is sometimes referred to as primary storage
- characteristics of secondary storage
- Media: physical material that holds the data and programes
- Capacity: how much a device can hold
- Storage devices: hardware that read data and programs from storage media. Often referred to as drives
- Access speed
- Provide access to flash memory, also known as solid-state storage
- characters are represented by positive and negative charges using ASCII, EBCDIC, or Unicode binary codes.
- Faster, durable and require little power
- It rotates and have read/write heads that move in and out
- Save files by altering the magnetic charges of the disks's surface to present 1s and 0s
- Density refers to how tightly these charges can be packed next to one another on the disk
- Platters are stacked one on top of another
- Tracks are rings of concentric circles on the platter
- Sectors refers to the sections a track is devided into
- Cylinders differientes files stored on the same track
- Located inside the system unit
- Disk caching: uses cache and anticipates data needs
- Hybrid drives: contain both solid-state and hard disks
- Redundant arrays of inexpensive disks(RAID)
- File comparison and file decomparision: replace repeating patterns with a token, leaving enough tokens so that the original can are rebuilt or decompressed
The 1s and 0s are represented by flat areas called lands and bumpy areas called pits
- Compact discs: store 700MB; widely used for storing music
- Digital versatile discs: DVD drives and CD drives are very similar; store 4.7GB
- Blu-ray Discs
Three types
- Read-only discs: cannot be written or erased by the user
- Write-once(R for recordable) discs: can be written on once
- Rewritable(RW for rewritable):
¶ Chapter8 Communications and Networks
- Texting
- E-mail
- Videoconferencing
- Electronic commerce
Using computer network to link people and resources
Electronic systems that transmit data from one location to another
Basic parts:
-
Sending and receiving devices
-
Connection devices: act as an interface between the sending and receiving devices and the communication channel
They convert outgoing messages into packets that can travel across the communication channel
-
Data transmission specifications: rules and procedures that coordinate the sending and receiving devices
-
Communication channel: the actual connecting or transmission medium that carries the message. It can be physical wire or cable, or it can be wireless
Carry data from one computer to another
Most use radio waves to communicate
-
Cellular(蜂窝网络):uses multiple antennae(cell towers) to send and receive data within relatively small graphic regions(cells)
-
Bluetooth: short-range radio communication standard
-
Wi-Fi(Wireless fidelity): uses high-frequency radio signals;standard is 802.11a(g,n,ac,ax)
-
Microwave: sometimes referred to line-of-sight communication because it can only travel in a straight line; used in sending data between buildings in a city
-
WiMax(Worldwide Interoperability fir Microwave Access): extends the range of Wi-Fi networks using microwave connections.
-
Satellite: Intelsat(the International Telecommunications Satellite Consortium system):
Uplink is a term relating to sending data to the satellite
Global position system(GPS) uses satellite
-
Infrared: sending and receiving devices mustbe in a clear view of one another without any obstructions
- Twisted-pair cable: telephone lines or Ethernet cables
- Coaxial cable
- Fiber-optic cable
Telephone lines are designed to carry analog signals, while the coputer use digital signals, so you need to use modem to conver digital to analog
- modem is a short for modulator-demodulator
- Modulation means the process of converting from digital to analog
- Transfer rate is measured in Mbps
- Three types:
- DSL(digital subscriber line): use standard phone lines
- cable modem: use coaxial cable
- wireless modem, or WWAN(wireless wide area network) modem: almost all hace built-in wireless modem
- Copper lines, knwon as T1 lines,could be combined to formhigher-capacity options known as T3 or DS3 lines
- The above lines have been replaced by faster optical carrier(OC) lines
- Used to use dial-up service, but replaced
- Cellular service providers
- Digital subscriber line(DSL) services: use existing telephone lines; ADSL is one of the most widely used types
- Cable service
- Fiber-optic service(FiOS)
- Satellite connection services
¶ bandwidth
The width or capacity of the communication channel
- Voiceband, or low bandwidth
- Medium band: connect midrange computers and mainframes; capable of high-speed data transfer
- Broadband: widely used for DSL, cable and satellite connection
- Baseband
- https(hypertext transfer protocol secure)
- TCP/IP(Transmission Control Protocol/Internet protocol): identifying sedning and receiving devices; breaking information into small parts or packets
- Identification: use IP(Internet protocol) address; use DNS(domain name server) convert text-based addressto IP address
- Packetization
- Node
- Client
- Server
- Directory server
- Host
- Router
- Switch
- Network interface cards
- Network operating systems
- Network administrator
- Bus network
- Ring network
- Star network
- Tree network
- Mesh network
- Client/server networks
- Peer-to-peer (P2P) network
- Intranet
- Extranet: a private network that connects more than one organizations
- firewall: proxy server
- Intrusion detection system(IDS)
- Virtual private networks(VPN)
¶ Chapter9 Privacy,Security and Ethics