What is this sentence meaning?

To play (a card other than a trump) from a suit different from that of the card led.

the card led’? What’s the meaning of ‘led’?
By the way, I don’t think I know how to play this kind of card.

This is talking about a game using playing cards.
There are four suites in a deck (set) of cards - diamonds, hearts, clubs and spades.
My guess is ‘the card led’ = the card that has most recently been played.