What is castling?

Sort:
NUb182
So I just started and when I played my cousin, he did a move that moved both the king and the rook at the same time. I don’t know how to do this and what it is. Thanks
KeSetoKaiba

Here you go:

https://www.chess.com/learn-how-to-play-chess 

The only legal move in chess where two pieces move in one motion is called "castling" and it involves the King and Rook (like your friend did). Check this link under "special moves" in chess. The three special moves are Castling, en passant and promotion. 

NUb182
Thank you so much!
Abdalla123Alali
https://youtu.be/FcLYgXCkucc watch this about castling
Abdalla123Alali
https://youtu.be/FcLYgXCkucc