A computer is a machine for manipulating data according to a list of instructions. Modeling a real physical system in a computer is called simulation. The notion that the universe is a computer is as old as Isaac Asimov's story The Last Question in the '50s and work by computer scientists Ed Fredkin and Konrad Zuse in the '60s. The computer is frequently involved in assisting in the creation or discovery of new representations of information.
Computers are our favorite metaphor at the moment, so maybe we see everything as computers. Computers are great to have because you can write to a friend on the other side of the world without sending it by mail, but they can be very addictive. The defining feature of modern computers which distinguishes them from all other machines is that they can be programmed. In most computers, individual instructions are stored as machine code with each instruction being given a unique number (its operation code or opcode for short). This contrasts with very early commercial computers, which were often one-of-a-kind and totally incompatible with other computers. In a few years, computers would pop up at universities, government agencies, banks and insurance companies. You've jumped from working on quantum computers to saying, oh, by the way, the universe is a gigantic quantum computer.
Viruses are software programs, and they can do the same things as any otherprograms running on a computer. Viruses usually operate without the knowledge ordesire of the computer user. Sometimes even an experienced user will not realise that a computer is infected with a virus. Install antivirus software if you do not have it installed. A virus may also be destroying your files or disclosing them to others who aren't otherwise allowed to see them. So a lot of people lost time, money, and irreplaceable data when the CIH virus activated simply because they didn't take basic precautions to protect themselves. If you're notified that your computer is sending a virus orparticipating in DoS attacks, you should immediately unplug thenetwork cable and reformat and reinstall your operatingsystem. Computer viruses are so abundant in number and varying in description that they are somewhat difficult to define. Anti-virus programs can be set to run system checks at every boot (each time you turn on the computer), daily or weekly.
Simply stated, the goal of computer security is this: keep your computer-based possessions-your computer system (CPU cycles, memory, disk space, and Internet connectivity and speed), the software you've purchased, and the files and folders you've created-yours unless and until you explicitly give them to others. The Internet is a powerful resource for finding and using the work of others to enhance your computing resources.
The interaction between the user and the computer is the locus of negotiation for performing the task. That is, the computer is a collection of representations used for creating and manipulating representations. Fifth generation of computer is the development of softwares to enhances computer works and its robotic applications. Some people usethis comparison to say that the computer is better than the brain; somepeople say that the comparison shows that the brain is better than thecomputer. The computer is faster atdoing logical things and computations.