The terms spyware and adware are often used interchangeably. Both of these terms are used to describe software which can display advertisements. However, there is one major difference between these two: spyware gets onto the user’s computer through illicit means.
With adware, the user agrees to have the adware program installed in exchange for something else. For example, the program Eudora will allow users access to shareware for free but they must agree to receive advertisements. The key word here is “agree.” Adware will not attempt to mislead users and is offered in exchange for a service.
An example of adware includes the file sharing program Eudora. Rather than asking users to pay a registration fee, it asks them to agree to receive advertisements. On the other hand, Gator software is a type of spyware. When users visit certain websites, spyware is installed on the users’ computer through some sort of deceptive manner. The company behind Gator as well as the website where the spyware was installed will both receive revenue.