Computer :: science

ComputerAbout two hundred years before, the interchange estimator started to appear in the dictionary. Some multitude even didnt complete what is a computer. However, well-nigh of the people today not just discerning what is a computer, but understand how to use a computer. Therefore, computer turn over more and more popular and historic to our society. We can use computer everywhere and they are very useful and helpful to our life. The speed and true statement of computer made people felt confident and reliable. Therefore, many eventful information or data are saved in the computer. such(prenominal) as your diary, the financial situation of a oil company or some secret intelligence of the military department. A lot of all important(p) information can be found in the memory of computer. So, people may ask a question Can we make trustworthy that the information in the computer is safe and nobody can err it from the memory of the computer? Physical hazard is maven of the causes of destroying the data in the computer. For example, send a flood of coffee toward a personal computer. The heavy disk of the computer could be endangered by the flood of coffee. Besides, adult male caretaker of computer system can cause as much as harm as any physical hazard. For example, a cashier in a bank can transfer some money from one of his customers account to his own account. Nonetheless, the most dangerous thief are not those who work with computer every day, but youthful amateurs who experiment at night --- the hackers. The term hacker may have originated at M.I.T. as students jargon for classmates who labored nights in the computer lab. In the beginning, hackers are not so dangerous at all. They just stole computer term from the university. However, in the early 1980s, hackers became a group of criminals who steal information from otherwise peoples computer. For preventing the hackers and other criminals, people need to set up a just security system to prote ct the data in the computer. The most important thing is that we cannot allow those hackers and criminals entering our computers. It means that we need to design a lock to lock up all our data or using identification to verify the identity of someone seeking access to our computers. The most common method to lock up the data is using a password system. Passwords are a multi-user computer systems usual first class of defense against hackers.