A poker freeroll is a type of a poker tournament in which the player can win a cash prize, but you don't have to pay an entry fee in order to compete in it. While the prizes aren't as high as in the tournament in which there are entry fees, still, many poker sites do offer some good prizes in their freerolls.

Freerolls script by Poker Freerolls Schedule

The poker freerolls were invented in the 1960s in Las Vegas, when some casinos tried to attract VIPs by offering free poker tournaments with actual prizes. The poker freerolls began to be popular online, as many online casinos created their own promotional freerolls poker rooms to attract new players to their website.

The stake for a poker tournament is usually raised through the buy-in fees, but in poker freerolls, the entire sum is raised from sponsorship from a company which promotes its products this way. Usually, it's an online poker company which also has poker rooms and tournaments for real money, the idea being that some freerolls players, as they feel their poker abilities improved, decide it's time to use their newly acquired skills and play for some higher stakes, for real money. The money won through poker freerolls can be usually converted to credits for the real money games.

Poker freerolls are a great way for beginners to improve their poker skills without risking any money, but they can be useful for the advanced players as well, being a good way of trying the effectiveness of various new game strategies, which you consider to be too risky to try out first in a game for real money. If you get lucky, you can even win some money, but even if you don't, your poker skills will be greatly improved as you will learn many new tricks and nuances of the game.

The fact that there is a prize makes the game more similar to those on real money, rather than to those on play money. Players usually take much higher risks when using play-money, hanging on to every hand, because they know there's not much to lose. On freerolls, as there is a cash prize involved, the players try to be more careful when playing and this makes the quality of such games far higher and the tournaments are better way to learn to play real poker than the games in which the players play just for fun, with play money.
Whether you play to improve your poker, to win some money, or just for fun, the poker freerolls are going to be some entertaining poker games for you.