There are 52 cards in game, the ranking of the cards from high to low, is:
In standard poker there is no ranking between the suits (for the purpose of comparing hands), so for example the queen of hearts and the queen of spades are equal.
A poker hand consists of five cards. The categories of hand, from highest to lowest, are listed below. Any hand in a higher category beats any hand in a lower category (so for example any three of a kind beats any two pairs).
If there are no wild cards, this is the highest type of poker hand: five cards of the same suit in sequence.
Four cards of the same rank - such as four queens. The fifth card, known as the kicker, can be anything. This combination is sometimes known as "quads".
This combination, sometimes known as a boat, consists of three cards of one rank and two cards of another rank.
Five cards of the same suit. When comparing two flushes, the highest card determines which is higher. If the highest cards are equal then the second highest card is compared; if those are equal too, then the third highest card, and so on.
Five cards of mixed suits in sequence.
Three cards of the same rank plus two unequal cards. This combination is also known as Triplets or Trips.
A pair consists of two cards of equal rank. In a hand with two pairs, the two pairs are of different ranks (otherwise you would have four of a kind), and there is an odd card to make the hand up to five cards.
A hand with two cards of equal rank and three cards which are different from these and from each other. When comparing two such hands, the hand with the higher pair is better.
Five cards which do not form any of the combinations listed above. This combination is often called High Card and sometimes No Pair.