The lowest of all the hands in poker is the high card. In Texas Hold'em poker, this means that none of your hole cards formed any combination with the community cards. For example, you got a Jack and 8, then, the community cards gave an ace, 3, king, 6 and 7. You are also short of one spade to make a flush. Your jack now is your high cards. This poker hand can easily be beaten by any pair.
A pair is composed of two same cards. Examples are two 9's, two jacks, or two aces. In poker, the pair is the second lowest hand. You can also get two pairs. The pair is what you can commonly get in poker.
Three of a kind in poker is like a pair, but instead of two cards of the same kind, you have three. This is the third lowest hand in poker, but even this is not common to get.
The next one in rank is the straight. This is not one of the common hands you'll get in poker, so if you catch this, you might want to raise. A straight is composed of five cards formed in succession such as 3 to 7.
Another powerful hand in poker is the flush. In poker, a flush is composed of five cards of the same suit. For example, 3, 5, Jack, Queen and Ace of hearts. A flush beats the straight and all else below it.
Next in line is the full house. A full house is a three of a kind and a pair put together. The full house beats the flush. The four of a kind is higher than the full house. In poker, you get a four of a kind when you get all the cards of a kind, like four 8's.
The four of a kind can easily be beaten by a straight flush, which in turn can be beaten by the royal flush. A straight flush is five cards in succession, and these cards are of the same suit. An example is 4 to 8 of diamonds. The rarest hand in poker, the royal flush is a straight flush, but with a twist. In poker, the royal flush is also composed of five cards of the same suit, but they are not just in any succession. They have to be the highest cards in poker - 10 to Ace.