Here is how poker hands rank:
Royal Flush
This is the best possible hand in standard five-card Poker. Ace, King, Queen, Jack and 10, all of the same suit.
Straight Flush
Any five-card sequence in the same suit.
Four of a Kind
All four cards of the same value.
Full House
Three of a kind combined with a pair.
Flush
Any five cards of the same suit, but not in sequence.
Straight
Five cards in sequence, but not in the same suit.
Three of a Kind
Three cards of the same value.
Two Pair
Two separate pairs.
Pair
Two cards of the same value.
High Card
If a Poker hand contains none of the above combinations, it's valued by the highest card in it.