What is spyware?

Spyware is often confused with viruses, but it's actually a completely different type of harmful software.  Spyware is marketing software which runs on your computer, usually without your knowledge. It falls into two categories:
  • Adware - This software uses your computer to present you with advertising. The most common type generates forests of pop-up ads, but it can also change your home page and "hijack" your browser so that when you try to go to a website you want, instead you're redirected to an advertiser's website.
  • Spyware - This is software that keeps track of your activities on the computer and periodically sends this information to the marketers. The more harmless type tracks information about your browsing habits (ex. what type of websites you visit the most), but it could also potentially keep track of more private information you're typing, such as account numbers and passwords.