In DayZ you can communicate by text on three different channels and with voice by using the built-in Voice Over Net system.
You can change chats with [,] and [.] or with up/down arrows when the chat line is open. The available channels are:
- Group char (green)
- Vehicle chat (yellow)
- Direct chat (white)
Having a plugged in and configured microphone helps interacting with other players largely and is a very popular method of communicating in the game.
Voice chat can make a large difference during your first contacts with other survivors. After all you can tell what you want faster than write it. When you hold down [CAPS LOCK], beside the chat field a microphone will appear, showing that you're using voice chat. The colour of the icon depends on the chosen chat.
Right after entering the game, make sure you're on direct chat (white colour). In case of coming across another player, you'd rather write to him than to a non-existent group - the same applies to voice chat which uses the same channels. The direct conversation range is maximally 80 metres, but at such distance your voice can be barely heard.