Internet games (also known as online games) are games that are played online via the Internet. They are distinct from video and computer games in that they are normally platform independent, relying solely on client-side technologies (normally called 'plugins'). Normally all that is required to play Internet games are a web browser and the appropriate plugin (normally available for free via the plugin maker's website). A game played in a browser is often called a browser-based game.
An Example Flash Game: