Tight Aggressive and Loose Aggressive, respectively.
TAG players generally don't play many hands, mostly only the higher quality hands, and when they do play them, tend to play them quite aggressively (Dan Harrington for example, although he's more tight than most). LAG players like to get involved in a lot of pots, and play a wider range of hands so it is harder to put them on hands. They are also very aggressive with their hands. Phil Ivey usually plays a LAG style.
There's also Tight Passive (TP)--a rock... tight and usually only bets with strong hands, and Loose Passive (LP)--calling station... plays a lot of pots but rarely shows aggression, and rather just keeps calling off.
TAG and LAG are considered superior to TP and LP, because of the importance of aggression in NL Hold 'em.