Spectate

If you wish to watch a match without playing, you can spectate a match. A spectator can fly around a Map freely or follow any player from their point of view. The act of spectating is commonly called "speccing".

When you have joined a team but are currently not alive, you are also spectating, but you cannot fly around freely for obvious reasons. On some servers, you can spectate your teammates from their point of view while you're not alive.