Typically though, the Joker is treated as a wild card which you can assign any value you wish. Scoring (hand ranking) is done identically to without wild cards, except that now 5 of a kind is possible, and that is the best hand. (5 deuces beats a royal flush, and 5 Aces is the best possible hand.)
It means that the joker is a wild card. A wild card is one that can be substituted for any other card value. It is hence a very powerful card that can be used to complete all kinds of poker hands depending on which card we are missing.