The rook traverses in straight lines along ranks and files. Both players have 2 rooks each at the beginning of a chess game. The rook is considered to be worth more than one light piece and less than two light pieces.
In the opening, the rooks are more or less passive, one of the two rooks participates by castling the king. In the middlegame, usually the first thing to do is to connect the rooks on the first rank. Then, the second thing is to identify the key files and open them and occupy them with the rooks. A file is called half open if your rook is shooting into an enemy pawn. A file is called open if there are no pawns on that file. A rook endgame is when both opponents each have a king, one or more pawns and one rook. Rook endgames have a strong draw tendency in the sense that there are many different defensive possibilities in such endgames. Probably because the rook is quick at stopping and grabbing enemy passed pawns. Also because the rook can cut off the enemy king from passing a certain rank or file.
With more and more pieces being exchanged off the board, the rook increases in strength. The rook is great at attacking and supporting the other pieces both positionally and dynamically. The rook can defend against other heavy pieces but is less good at defending against Q+B, Q+N, N+B and B+B piece combinations. A rook can become trapped in many different ways because of the own and the enemy pawns. The rook prefers pawn structures where there are many open ranks and files. The rook likes to have open spaces because it is vulnerable to diagonal attacks. The bishop pair is great at catching rooks.
A common and recommended rook strategy is to open a file, occupy it with the rook and then enter the enemy's second rank with the rook. White wants to get the rook to the 7-th rank and black wants to get the rook to the 2-nd rank. From that position, the rook can grab material, limit the enemy king's movements and create opportunities for grabbing material and checkmating the opponent.