From https://www.chess.com/terms/castling-chess
Castling is a special move in chess where you do multiple unique actions. First of all, it is the only move where you may move two pieces in the same move! Secondly, castling is the only time in chess when it is legal to move the king more than one square! Third, it is the only move that both develops your rook and protects your king. Castling can be performed on the kingside (notated as 0-0) or queenside (notated as 0-0-0).
Castling involves the king and a rook. As mentioned, there are many rules to castling: The first is that you may only castle if you haven't moved your king and your rook (on the side where you want to castle). The second rule is that no piece can be between your king and the rook on the side where you want to castle.
Since there are no pieces in between the king and the rook and because neither piece has moved, White can castle kingside! How do we do this? The white king moves two squares (from e1 to g1), and the white rook moves from h1 to f1.
So how do we castle queenside? We still move the king over two squares (this time from e1 to c1), and then the rook moves from a1 to d1.
From https://www.chess.com/terms/castling-chess
Castling is a special move in chess where you do multiple unique actions. First of all, it is the only move where you may move two pieces in the same move! Secondly, castling is the only time in chess when it is legal to move the king more than one square! Third, it is the only move that both develops your rook and protects your king. Castling can be performed on the kingside (notated as 0-0) or queenside (notated as 0-0-0).
Castling involves the king and a rook. As mentioned, there are many rules to castling: The first is that you may only castle if you haven't moved your king and your rook (on the side where you want to castle). The second rule is that no piece can be between your king and the rook on the side where you want to castle.
Since there are no pieces in between the king and the rook and because neither piece has moved, White can castle kingside! How do we do this? The white king moves two squares (from e1 to g1), and the white rook moves from h1 to f1.
So how do we castle queenside? We still move the king over two squares (this time from e1 to c1), and then the rook moves from a1 to d1.