Spyware is any technology or programming on your computer that covertly gathers information; the data is then sold to advertisers or to other interested parties. The type of information harvested from your computer differs. Some spyware tracks your system information only, such as your type of Internet connection and type of operating system. Other spyware collects personal information such as detailed tracking of your Internet surfing habits, or worse, harvesting of your personal files.
Spyware is installed without the user's consent (if you give consent for a company to collect your data this is no longer considered spying, so read online data disclosure statements carefully before consenting). Some people don't object to general spying that tracks Internet and software trends as long as personal identifying information is not included; others object to any information being taken from their computer without their consent. Either way, the software or device that gathers the information is called spyware.
Spyware installation on your computer can be initiated by visiting a website, viewing an HTML e-mail message or by clicking a pop-up window. The download process is unannounced so that you will remain unaware that your computer has accepted spyware. This deceptive method of filling your computer with tracking software you didn't request is called a drive-by download (there are options available to you for spyware removal once your computer has been infected.). For more information on how spyware attaches itself to your computer, read: How Did Spyware End Up on My Computer?