Aggressive
A style of play characterized by a large amount of betting, raising and re-raising. An aggressive player will be selective about which cards to play. However, when they elect to enter a pot or hand, will play the hand very strongly.
Passive
A passive player is the type that is quite easy to play against and beat. You do NOT want to be a passive player. This player will very rarely raise and will do a lot of checking and calling - a losing proposition. The passive player is the ideal prey for "The Bully."
Bully
This word can be used as a verb or a noun. When a player is a bully, he plays very, very aggressively to try and get other players, particularly 'passive players' to fold what may be the best hand. A Bully bluffs a lot, and raises a lot. In essence, this player tries to bully the rest of the players into folding. He is not necessarily playing cards, he may just be playing the player!
Maniac
This kind of player can cause the entire table to go on 'tilt' (playing poorly, usually because of becoming emotionally upset). He plays just about any cards, often-times capping the betting and ends up winning the most unbelievable hands. The trouble with this type of player is that he gets the good player to react to him and play hands he would normally not play. If the strong players will have patience and not allow this maniacal player to get to them, then he will quickly burn himself out and return his 'temporary' wins to the rightful owners. In other words, he will do this so often that his 'crazy' style of play will lose more often than win. Be careful when playing at a table with this type of player.
Loose
The nature of this player is to be very liberal and very optimistic. He may not get to play much poker and if he has any starting cards that look remotely good to him, he will go ahead and play them on a wing and a prayer. That means he will see some winning possibility in any combination of starting cards and will normally follow all the way through to the end, just hoping that something will fall into place for him.
Tight
The approach of this player is to play very conservatively and gamble very little. He won't like to take chances, and usually has a very rigid set of guidelines by which he will play. This player is often referred to as a rock. A tight player usually means business when he stays in a hand. Of course, this is a good thing for him, because he can bluff and get away with it because he is almost always believed when he bets or raises.