Adware: Definition

Adware is software that initiates advertising functions. It may be integrated into a program or bundled with another program. It is usually used to recover development costs, or earn ongoing revenue. In some cases it may allow a program to be provided to the user free of charge, or at a reduced price. The advertising income may allow or motivate the developer to continue to develop, maintain and upgrade the software product.

Some adware is also shareware, and so the word may be used as a term to differentiate between types of shareware. Adware is primarily advertising-supported. Users may also be given the option to pay for a "registered" or "licensed" copy to do away with the advertisements.

Adware can maliciously download and install "potentially unwanted programs" (PUPs).