Spyware is any piece of software that secretly installs itself on your computer and starts tracking and recording your computer activities. In general, spyware comes secretly bundled within freeware and shareware software that is downloaded from the Internet. Spyware programs work in the background without your knowledge and collect essential information related to you. This may include your usernames, passwords, bank account numbers, and any other personal and confidential information. This information is usually sent to external sources for malicious purposes. Unlike viruses, spyware programs usually do not display any error messages which make it difficult to detect them. In addition, most computers only have an antivirus program installed and not an antispyware program.