Spyware refers to programs that use your internet connection to send information from your personal computer to another computer without your knowledge or permission. This information can include browsing habits, downloads, or personal data. Spyware is often installed secretly when a user downloads other software and can slow a computer's performance. Anti-spyware software can prevent spyware installation or detect and remove any spyware already installed. Major anti-virus companies now include anti-spyware features to protect against this type of unwanted program.