暨南大学计算机概论期末考

暨南大学计算机概论期末考 Short Answer Questions (Final Version) 1) Is there a difference between data and information? Technology professionals define data as the symbols that represent people, events, things, and ideas. Data becomes information when it is presented in a format that people can understand and use. As a general rule, technically speaking data is used by machines, such as computers; information is used by humans. 2) How does RAM differ from hard-disk storage? RAM holds data in circuitry that’s directly connected to the system board, whereas hard-disk storage places data on magnetic media. RAM is temporary storage; hard-disk storage is more permanent. In addition, RAM usually has less storage capacity than hard-disk storage. 3) Why are hard disk drives so popular? Hard disk technology is the preferred type of main storage for most computer systems for three reasons. First, it provides lots of storage capacity. Second, it provides fast access to files. Third, a hard disk is economical. The cost of storing a megabyte of data is about 1/17th of a penny. 4) How is software categorized? The two main categories are system software and application software. System software is designed for computer-centric tasks, whereas application software is designed to help people accomplish real-tasks. System software and application software categories can be further divided into subcategories. 5) Is shareware the same as demoware? Shareware is copy-righted software marketed under a try-before-you-buy policy. Demoware is distributed for free and often comes pre-installed on new computers, but it is limited in some way until you pay for it. Unlike crippled or time-limited demoware, shareware was supposed to be fully-functioning software. And now, the term shareware is used today to refer to programs distributed by independent programmers, whereas demeware tends to be used when referring to trial versions of software from big software firms, such as Microsoft, Adobe Systems, and Oracle. 6) What does an operating system do? The most obvious responsibility of your computer’s operating system is to provide an environment for running software. The operating system interacts with application software, device drives and hardware to manage a computer’s resources. Its main tasks are as follows: 1) Manage memory 2) Manage processor resources 3) Keep track of storage resources 4) Ensure that input and output proceed in an orderly manner 5) Establish basic elements of the user interface 7) Describe six major events happen during the boot process. Power up: turn on the power switch and the power light is illuminated Start boot program: the microprocessor begins to execute the bootstrap program that is stored in ROM Power-on self-test: the computer performs diagnostic tests of several crucial system components. Identify peripheral devices: the operating system identifies the peripheral devices that are connected to the computer and checks their settings. Load operating system: the operating system is copied from the hard disk to RAM. Check configuration and customization: the microprocessor reads configuration data and executes any customized startup routines specified by the user. 8) What are the strengths of Linux? What are the weaknesses of Linux? Strengths: Linux is unique because it is distributed along with its source code under the terms of a General Public License (GPL). It is primarily distributed over the Web. It shares several technical features with UNIX, such as multitasking, virtual memory, TCP/IP drivers, and multiuser capabilities. It is a popular operating system for e-mail and Web servers. Weaknesses: 1. More tinkering than Windows and Mac desktop operating systems. 2. The limited number of programs that run under Linux discourages many nontechnical users from selecting it. 3. High-quality open source software are targeted toward business and technical users. 9) How are computer networks classified? PAN (personal area network) is a term sometimes used to refer to the interconnection of personal digital devices within a range of about 30 feet (10 meters) and without the use of wires or cables. A NAN (neighborhood area network) provides connectivity within a limited geographical area, usually spread over several buildings. A LAN (local area network) is a data communications network that connects personal computer within a very limited geographical area ------usually a single building. A MAN (metropolitan area network) is a public high-speed network capable of voice and data transmission within a range of about 50 miles (80 km). A WAN (wide area network) covers a large geographical area and usually consists of several smaller network, which might use different computer platforms and network technologies. 10) Describe the network topologies: Star, Ring, Bus, Mesh, Tree A star topology connects all devices in a circle, with each device having exactly two neighbors. Data is transmitted from one device to another around the ring, which is infrequently used in today’s networks. A bus topology uses a common backbone to connect all network devices. The backbone, as a shared communication link, carries network data. A mesh topology connects each network device to many other network devices. With multiple connections, data can follow alternative functioning links to reach its destination. A tree topology is essentially a blend of star and bus networks, which offers excellent flexibility for expansion and is widely used. 11) Describe the Protocols used on the Internet: TCP,IP,HTTP,FTP,POP,SMTP TCP is the transmission control protocol which creates connections and exchanges packets of data. IP is the internet protocol which provides with unique address. HTTP is the hypertext transfer protocol which exchanges information over the Web. FTP is the file transfer protocol which transfers files between local and remote host computers. POP is the post office protocol which transfer mail from an e-mail server to a client inbox. 12) How are domain names related to IP addresses? Every Any domain name corresponds to a unique IP address that has been stored in a database called the Domain Name System (DNS). Any computer that hosts the DNS is referred to as a domain name server. A domain name request is routed through your ISP to your designated domain name server, which searches through its DNS to fine a corresponding IP address. The IP address can then be attached to packets, such as requests for Web pages. 13) What’s the difference between the Web and the Internet? The Web is one of the Internet’s most captivating attractions. Although the terms Internet and web are sometimes used interchangeably, they are not the same. The web is an interlinked collection of information; The Internet is a communications system used to transport that information from computers that store it to clients who want to view it. 14) What are the most common e-commerce business models? B2C (business-to-consumer): individual consumers purchase goods and services from online merchants. C2C (consumer-to-consumer): consumers sell to each other at popular online auctions. B2B (business-to-business): one enterprise buy goods or services from another enterprise. B2G (business-to-government): this e-commerce aims to help businesses sell to governments. 15) How does POP mail compare to Web-based e-mail? Install and use e-mail Use a browser to work client software with your e-mail Your computer’s hard Its server disk Control: POP mail gives you more control over your messages. Security: Web-based e-mail might be safer than POP mail. Travel: Web-based e-mail is more convenient for traveling.