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Information literacy Knowing how to find data from several sources, select relevant material, analyse and organise it into a form that can be used to make decisions. Computers have become the tools people use to access and manage information. Information technologists are people who analyse and design the tools. What is a computer? Tradition definitions of computers include �6�1 A machine that accepts data and processes it into use information. �6�1 A computer is a binary, digital, electronic, stored program machine. �6�1 While a computer is commonly a digital machine, analogue machine do exist. An electronic device, operating under the control of instructions stored in its own memory unit, that can accept data (input), process data arithmetically and logically, produce results (output) from the processing and stores results for future use. Many computers receive and send data (communicate) across networks LAN and Wan. A computer system consists of hardware and software. What is hardware? Hardware Hardware is physical devices or components that can be physically handled – you can thou it. Input Devices Input devices convert data that humans collect into coded electrical signals that a computer can process. The central processing unit The electronic processing takes place in the CPU. The CPU consists of �6�1 A control unit that controls all of the computer’s functions and an �6�1 Arithmetic and logical unit (ALU) that performs any calculation Memory Memory holds all programs and What is RAM currently open? Data (notes) Word processor Output devices Output devices convert the computer’s electronic signals back into information Secondary storage devices These devices store programs and data permanently. The programs and data are not necessarily (or likely to be) in current use. . DVD CD Communication devices These devices enable a computer to connect to another computer. List the six different type of hardware? Secondary storage(external), input, processor, output , memory, Communication. Name eight pieces of hardware USB, keyboard, monitor, screen, RAM, ROM, VDU, Modem. The system unit and peripheral devices The system unit is the computer box. Peripheral devices are any devices around the outside, or in other words, plugged into the (back of) the machine. Peripheral devices include the key board, mouse, printer, joy stick and others. Peripheral devices are any devices around the outside, or in other words, plugged into the (back of) the machine. Peripheral devices include the keyboard, mouse, printer, joy stick and others. What else does a computer have? Software Software is a computer program ,which is a detailed set of instructions that directs a computer to perform the tasks necessary to process data into information. These instructions are written in languages that computer can interpret. Software includes computer games, a word processing packing, an accounting package, amongst Definition of a computer system �6�1 A computer system is the configuration of hardware and software, functioning together, to process data into useful information, in order to achieve a purpose for a human user. What is data? �6�1 Data is raw facts, be they numbers, words, images and sounds, that can be input into a computer. . Mary a name is a piece of data What is information? �6�1 Information is processed data, that has meaning and is useful. . John is a list of names who scored an A grade on an exam John A Chai A Pam A . Commodore $23 500 Magna $21 500 Falcon $19 800 The system unit contains the �6�1 Motherboard �6�1 CPU �6�1 Memory �6�1 Other electronics It is where the computer program instructions are executed and the data is manipulatedThe Processor CPU The CPU interprets and carries out basic instructions that operate the computer, the CPU contain the �6�1 Control unit and the �6�1 Arithmetic logic unit Control unit The control unit directs and coordinates the computer’s operations. For every single instruction, the control unit repeats four basic operations, �6�1 Fetching �6�1 Decoding �6�1 Executing �6�1 Storing CPU speed The CPU’s speed may be measured in MIPS The number of millions of instructions per second Arithmetic/logic unit The ALU performs all calculations, which involve �6�1 Arithmetic operations 2+3 �6�1 Comparison operations age>=17 �6�1 Logical operations pass Processing instructions A CPU may begin executing a second machine cycle before completing the first-referred to as pipelining. Current CPU’s can pipeline up to 4 instructions. Storage within the CPU Registers temporarily hold data and instructions. The computer’s clock A System clock is necessary to control the timing of all computer operations. Each tick of the clock is referred to as a clock cycle. Clock speed is the speed at which a processor executes instructions. A hertz is one cycle per second and a megahertz is 1024 by1024 and a gigahertz is 1024 by 1024 by1024. Memory Memory is the temporary storage place for data and (program) instructions. Memory is measured in �6�1 Kilobytes 1024 bytes 2^10 �6�1 Megabytes 1024* 1024 bytes 2^20 �6�1 Gigabytes 1024*1024*1024 bytes 2^30 Representation of data Digital computers are built from many small electronic circuits. Each circuit, at any point of time can be turned OFF or ON. Hence these devices are called two state devices. Binary Digit 0and 1 Each off or on digital value is called a bit, short for binary digit. A 1 bit computer would be able to distinguish between two values-characters, symbols or numbers. Hardly sufficient for the characters on the keyboard Bits Characters 1 2 2 4 3 8 4 16 5 32 6 64 7 128 8 256
Since the 21st century, the human economy has developed high speed, the people live have had the change which changes with each new day, specially computer's application and popularization to economical and social life each domain. Along with the computer in the social life each domain's widespread utilization, the computer virus attack and the guard technology unceasingly is also developing, has brought the huge destruction and the latent threat for the computer system. It is reported that various countries suffer the computer virus infection and the attack event are counted by the 100 million, has disturbed the normal human society life seriously, has brought the huge latent threat and the destruction for the computer network and the system. Along with the computer, the network utilization popularizes unceasingly, thoroughly, will guard against the computer virus to receive various countries to take seriously more and more. In order to ensure system's security and unimpeded, therefore, studies the computer virus the measure to be imminent. This article obtains from computer's characteristic, to come the preliminary discussion to cope with the computer virus the method and the measure. 计算机Computer,、病毒 virus系统安全system safety
You've probably been sick before. It's not many cases, like the flu, you're sick because of a virus…tiny germs ready to multiply and spread from person-to-person, via handshakes or sneezes。你肯定生过病吧,很不爽,对吗?生病通常是因为感染了病毒。握手、打喷嚏都能让病毒繁殖传播。Computer viruses are no of germs, they are computer programs are usually designed by criminals to multiply and spread from computer-to-computer like a one makes it to your computer, it can erase your files, send emails without your permission or even communicate sensitive info to criminals。电脑病毒亦然。但不是微生物而是电脑程序。黑客设计的病毒程序会像疾病一样在电脑间传播一旦电脑感染了病毒,它会删除文件、私发邮件、甚至把私人信息泄露给犯罪分子。Let's take a closer look, because what we call computer viruses can actually be Viruses, worms or trojanswe’ll start with bugs hitch a ride when something, like a file, is shared between computers. This often happens via attachments sent in email or shared USB someone clicks to open the file, the damage is virus is now on that computer, where it starts to multiply and look for chances to hitch a ride to a new computer。电脑病毒可以细分为三种,普通病毒、蠕虫 、木马先来说说普通病毒。它通过电脑之间的文件共享来传播。通常会在附件或U盘中出现,一打开这种文件,电脑就会中毒。然后复制,等着感染下一台电脑。Like a sick human, it’s sometimes hard to to tell when a file has a this reason, the best defense is anti-virus prevents viruses from getting to your computer and removes them when they are found。和人生病一样,有时候文件是否感染病毒也很难”确诊”。所以,最好的防护措施就是安装杀毒软件能防止电脑中毒,也能在发现病毒时及时清除。Now, worms are a little are programs that spread to computers without humans doing create worms to spread via computers that are connected in a network. They worm their way from computer-to-computer it's a small office or a global network like the Internet。蠕虫则更可怕,即使我们什么也没操作,它也能传播。只有电脑联网,蠕虫就会感染网上的病毒。不管是局域网,还是在整个互联网中。Usually, the worms find a back way to trick the computer’s software into letting them they're in, they look for the same backdoor in similar computers,wreaking havoc along the way。蠕虫擅长走”后门”。就是通过电脑软件的漏洞入侵。一旦被感染,蠕虫还会寻找其他电脑的”后门”,一路披荆斩棘地破坏下去。The best defense is keeping your computer software up to date at work and helps close the doors and prevent problems。最好的防护措施是,更新系统、修复漏洞,门关好了,蠕虫就爬不进来了。Trojans, our last example, are sneaky the real trojan horse, they’re a you fall for it, you end up downloading a virus from the may appear to be a game or useful software, but hidden inside is a program that can cause example, these programs can open new backdoors,giving criminals access to your computer and information over the Web。木马则是最最阴险狡诈的病毒。像传说中的特洛伊木马,它也善用诡计,一个不小心就可能从网上下载木马。木马病毒会伪装成游戏或者常用软件,有些木马还会给电脑开新的”后门”,让犯罪分子轻易侵入你的电脑获取信息。Not avoid trojans, only download software from sites you like washing your hands and covering your cough,you have to be aware of what causes problems to avoid them。可怕吧?要防木马,你必须只在信任的网站上下载软件,提高警惕,时刻注意网络安全,就像咳嗽要掩口,饭前便后要洗手一样。Keep your computer up to date and get anti-virus will help prevent problems and help you please…don't click on links, attachments and downloadable you know they're legit。还要经常更新电脑软件,安装杀毒工具。一边防患于未然,一边“亡羊补牢”。另外,陌生的链接、附件、文件也不要碰。除非能确认它们的安全性。Through a little awareness, you and your computer will stay happy and healthy。
Computer [By Kaiser3344]More than two hundred years ago, the invention of the steam engine,rumbled ushered in the industrial society; more than a hundred years ago,lamps, electrical world presents a multicoloured to humans; sixty years ago,computer generated, the human with the highly development track, the earth has become a village. Computer is gradually becoming the master of human production and use of computer to improve the production efficiency is very high. From the spacecraft to the research of nanotechnology, production from nuclear explosions to the pipeline, human production aspects are due to the use of computer and enhance production efficiency. USA ala Moss National Laboratory, a few big basketball court with a computer, can be used to simulate nuclear test, it a second operation of hundreds of millions of times,a few days to finish ourselves never finish the work. Even in ordinarycomputer industry, also plays an important role. For example, in the field of education, a teacher want to count a grade exam results, calculate theaverage, with the computer, a few seconds on the line, if calculated by hand, to a few to computer and Internet as the carrier, promote rapid economic growth. The Internet enables people to obtain information more convenient,so as to make the investment, production, sales and other aspects of thespeed, so that rapid development of the economy. USA former president Clinton proposed in 1992 to increase Internet information transmission speed of the "information superhighway" plan, make America stable economic growth, rapid is increasingly affecting the human way of life. The emergence of the Internet to eliminate regional disparities, so far apart from each otherpeople can get together and talk. Remain within doors, tour the of miles away, cleaning the house, Arabian Nights type ideashave been realized with the help of course, computer has many benefits at the same time, there are manyhidden dangers. So some people think that computer can do more harm than good, and hindered the development of society. This view is especially the emergence of Internet time is very short, it takes a long time to perfect and develop. Moreover, every thing has not onlyadvantages without fault. Nuclear energy can give great energy for human beings, but also in the human head enveloped nuclear explosion shadow;cloning is human scientific breakthrough, but human cloning is againsthuman and Internet is becoming more and more important, how should we do? A survey shows that, the great Russian Internet users only about three million, this makes us more profound understanding of why she isfading. In fact, the computer and the Internet is not popular, resulting ininformation, information due to occlusion of production is backward,backward in production led to the strength of the backward. The economyhas just taken off Chinese if don't want to lag behind, we must pay attention to the popularization of computer and internet. Fortunately, our country has"legend", "square", "Sina", "Sohu" and so on his computer and networkcompany, although far from their independent and Internet whirlwind blowing up, are you ready?好评
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