This normally happens invisibly to the user. Now I will attempt to explain Long Distance Calling Plans, It may be simpler. Just what can these things called Viruses do, and what you can do to protect yourself against them.
People can contract viruses in many ways, including sharing floppy disks with friends.
After all, most viruses were written to be spread and what better way to do that than to jump off on to an unsuspecting floppy and go for a ride. When the floppy is inserted into another PC the virus jumps off and now has a new home. Another way of getting viruses is on-line. You can download a virus and run it on your system without even knowing it, until its too late. Be Careful What You Download .