Computer viruses are software programs. They are created to spread from one computer to another.

A biological virus cannot replicate itself. A virus must inject its DNA into a cell to reproduce.

Similarly, a computer virus must hitch on to some other computer program. Then it can launch itself.

These viruses can be totally destructive or basically benign. When people think of computer viruses, they generally think of the former.

Most viruses spread easily via attachments. People should never open an email attachment unless they know the sender$.$