Adware is a legitimate, non-replicating program designed to display ads to the end user, often based on monitoring of browsing habits, and often in exchange for the right to use a program without paying for it. Some types of adware are also spyware and can be classified as privacy-invasive software. Adware can slow down a computer by using RAM and CPU cycles. Adware can also slow down a user's Internet connection by using bandwidth to retrieve advertisements.