Viruses are a man-maid programs or pieces of code that are loaded in your computer and run without your knowledge and/or against your wishes. They are harmful, just like biological ones, and they can do anything from self replicating, deleting data to transmit themselves from computer to computer in a network.
To protect you data and your computer from viruses you should buy an anti virus security program. This program will firstly clean you computer from the ones that are already in your computer and then to protect your P.C. By detecting and blocking the incoming ones.
There are three categories of viruses that it is best to be aware of:
The standard computer viruses are hidden in a normal program and activate only as the program is accessed. Then they infect other programs and copy themselves through the system. This kind of viruses are the easiest to be found by an anti virus program. The problem is that there are new kinds of viruses created almost every day by hackers so it is recommended to buy an anti virus that is always up to date so it can detect even the latest types of viruses.
A second type of viruses is the ones that spread though Email. These types of viruses activate as you access your mail and sends a copy of itself to everyone in your address book. Most of Email services already have some protection against these viruses, but as the first type of viruses, these can to be made almost every day. The best you can do is not to open any mail from someone you don't know and if it is from a trusted source, but it had a suspicious title, try to contact the source to confirm that it actually send that message.
You should also be aware of worms and Trojans. Worms are a subcategory of viruses that can copy themselves from computer to computer in a local network without needing to hide in programs. The best way to protect yourself from worms is to use a firewall. Trojans will appear to you as a useful program or software, but as soon as you install it, you will see the results. Some of them can only be annoying by adding desktop icons or changing you status if you use a instant messaging program, but some of them can seriously damage you computer by deleting system files or other information.
