The third part in this series of dangers to your computer is about adware, it is probably the least dangerous of the three so far to your computer, but it may just be the most annoying.

Adware or advertising-supported software is any software package which automatically plays, displays, or downloads advertising material to a computer after the software is installed on it or while the application is being used. Some types of adware are also spyware and can be classified as privacy-invasive software.

It is usually seen by the programmer as a way to recover programming development costs, and in some cases it may allow the program to be provided to the user free of charge or at a reduced price. The advertising income may allow or motivate the programmer to continue to write, maintain and upgrade the software product.

Some adware is also shareware, and so the word may be used as term of distinction to differentiate between types of shareware software.

What differentiates adware from other shareware is that it 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.