Poker hand ranking
In Texas Hold'em you get two cards that are your own (hole cards).
You combine them with the common cards (community cards) to make a 5 card poker hand.
You can use both your hole cards together with 3 community cards, or one hole card and 4 community cards, or all 5 community cards. In the last case, the best you can hope for is to split the pot.
You choose this based on what gives you the best poker hands. In online poker this is done automatically, but you still have to understand it of course.
Below is the best poker hands ranking from the top and downwards. In poker all suits are ranked equally.
Four of a kind
Three of a kind