Adware, or advertising-supported software, is any software
Computer software
Computer software, or just software, is a collection of computer programs and related data that provide the instructions for telling a computer what to do and how to do it....

 package which automatically plays, displays, or downloads advertisements to a computer. These advertisements can be in the form of a pop-up
Pop-up ad
Pop-up ads or pop-ups are a form of online advertising on the World Wide Web intended to attract web traffic or capture email addresses. Pop-ups are generally new web browser windows to display advertisements...

. They may also be in the user interface of the software or on a screen presented to the user during the installation process. The object of the Adware is to generate revenue for its author. Adware, by itself, is harmless; however, some adware may come with integrated spyware
Spyware is a type of malware that can be installed on computers, and which collects small pieces of information about users without their knowledge. The presence of spyware is typically hidden from the user, and can be difficult to detect. Typically, spyware is secretly installed on the user's...

 such as keyloggers and other privacy-invasive software
Privacy-invasive software
Privacy-invasive software is a category of computer software that ignores users’ privacy and that is distributed with a specific intent, often of a commercial nature. Three typical examples of privacy-invasive software are adware, spyware and content hijacking programs.- Background :In a...

Advertising functions are integrated into or bundled with the software, which is often designed to note what Internet sites the user visits and to present advertising pertinent to the types of goods or services featured there.