Poker players, and indeed entire poker games, can be characterised as either tight or loose:
A loose player stays in every hand until the showdown, bets and raises with mediocre hands, and although they can be lucky and ocasionally draw a great hand, they generally lose more money than they win.
A tight player folds most hands before ever making a bet. They don't spend money throwing chips into the pot to save earlier bets. They know a bad hand is a bad hand, and generally avoids bluffs.