Spyware: Spyware is a computer program often installs as a third-party component bundled with a freeware or shareware application, just like adware, making the distinction between the two somewhat vague. Spyware includes code used to gather and transmit information about the user or his or her behaviour to a third party. This statistical data often is collected without the knowledge or consent of the user.

Programs that, when installed on your computer, change settings, display advertising, and/or track Internet behavior and report information back to a central database. That''s usually an Internet marketing website. Spyware sometimes installed unintentionally by users along with other wanted software, and can be very hard to remove. Also known as malware.