About two hundred years before, the word "computer" started to appear in the dictionary. Some people even didn't know what is a computer. However, most of the people today not just knowing what is a computer, but understand how to use a computer. Therefore, computer become more and more popular and important to our society. We can use computer everywhere and they are very useful and helpful to our life. The speed and accuracy of …showed first 75 words of 2484 total…

…showed last 75 words of 2484 total…information to the computer for analysis. Although scientist have invented many kind of computer security systems, no combination of technologies promises unbreakable security. Experts in the field agree that someone with sufficient resources can crack almost any computer defense. Therefore, the most important thing is the conduct of the people. If everyone in this world have a good conduct and behavior, there is no need to use any complicated security system to protect the computer.