Player types

Aggressive/Passive
A player's aggression or passivity refer to how he plays a hand. Aggressive players are usually betting and raising while passive players tend to check and call. When a player who exhibits one style suddenly switches to a different style, look out. This can indicate she's holding a monster.

Loose/Tight
The looseness or tightness of a player refers to a players hand selection and how many hands he plays overall. A loose player will play more hands and show down some marginal cards. A tight player tends to stick to premium hands, thus playing few hands.

Weak
Players who "see monsters" where there aren't any are called weak. They tend to put their opponents on a single hand rather than a range of hands, and that hand is usually a big one. They will make "great laydowns" and take pride in them. Weak players are easily bullied by aggressive opponents.