Spyware is basically any piece of software that is installed in your computer without your knowledge. They can do a number of things like for example, taking over a part of your system, say your internet browser and always bring you to their site whenever you type an address. There are multiple versions of these kinda programs. Another common one keeps track of what you do online and offline and sends this information to its own company, or sells them to other companies.
by http://zuldevil.rocks.it March 03, 2004