VoiP, or Voice Chat, is a feature included in many different games. Voice Chat can be handled in different ways depending on the game. Some games do not allow voice chat in certain situations, and some games are completely unrestricted in voice chat. VoiP is a relatively new thing to consoles, as online play was not a widepread concept until the launch of the Playstation 3 and Xbox 360 (although it was reasonably popular on the Playstation 2 and Xbox consoles).
One option in some voice chat systems is to create a private channel for chatting, or a 'Private Chat', as it is also known. In a Private Chat, two players can discuss things without other players joining in. This feature can be performed in different PC games, as well as consoles. Some consoles also allow 'Parties' or 'Clans', where many people can be in a private channel at the same time.
Notable Uses of Voice Chat
With the release of Halo 3, there was a unique feature to cut down on 'mic spamming' online. This feature restricted players from talking unless they pushed a button to talk. Additionally, the system cuts off the talker after around 5-10 seconds. Many new players do not realise this feature is in place and will occasionally talk to fellow gamers without actually saying a word.
Endwar was a real time strategy game that supposedly was able to allow players to control their units using only their voice, should they choose to. This feature was unique at the time, and was generally not extremely well accepted, as it did not always work depending on the accents and voices of the players.