Online Poker Games doesn't have a basic strategy like blackjack or video poker. The best way to play a particular hand will change with every games and every player. For example, a showdown is not necessarily the preferred outcome. Tight (conservative) players with rags (poor hands) will quickly fold rather than put money in a pot that someone else will ultimately win. A good poker player with a bad hand will sometimes turn this to an advantage and steal the pot with aggressive betting. The same player with a good hand will lure unsuspecting bettors into the pot with tentative betting. Of course, other good poker players will recognize this obvious ruse and wager accordingly. It turns into an intricate games of, "He thinks that I think that he thinks that I think that he thinks that I have four kings. But I know that he knows that I know that he knows" And the games goes on.
Check-raising is playing a hand weakly in order to raise later in the same round of betting. It is possible that you will win the pot right there when you check raise. At the very least, you will probably reduce the opposition to one or two players, which is what you usually want.
SLOW PLAYING VERSUS CHECK RAISING
Slow playing is not the same thing. It is playing a hand weakly on one round of betting in order to suck people in for later bets. Typical slow plays are to check if there has been no bet or just call a bet rather than raise. In other words, you take no action beyond what is necessary to stay in the pot. You give nothing away about the strength of your hand.
When you check-raise you usually want to reduce the number of your opponents, but when you slow play you are trying to keep as many players in the pot as you can, expecting to collect later bets from them as a result of your early deception. Obviously, since you are not worried about having many players in the pot and are not particularly concerned about giving them free cards, you must have a very strong hand to slow play - much stronger than a hand with which you would check-raise. In seven-card stud it might be three-of-a-kind on the first three cards or a flush or full house against one pair. In hold 'em it might be the top set of trips after the flop with no possible straight or flush draw showing. In draw lowball it might be something like a pat.