Initially free internet services and free software were made available by the individuals with the pure thought in mind to share information. While some entrepreneurs found these internet services and free software as great tools to make money and started loading the free services and software with advertisement.
For sometime it worked well, but when the ad market became much more difficult out of desperation to make free services and free software pay off it gave rise to Adware. In technical terms advertising-supported software or Adware 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.
To be more precise Adware is a type of program that shows add like any other commercial websites with the only difference, Adware are controlled by the program instead of by visiting a Website. Still some of them do not pose a problem as they make it obvious that viewing the ads pays foe a free piece of software. These kinds of ads are displayed only when that particular program is run by you.
But those that are real culprits are the ones that are set to start whenever you start your computers. It even displays ads when the user is not running ad supported software he chooses to install. The worse types of Adware’s are those that keep on running even when the software it brought was uninstalled.