This is a lesson about promoting pawns to a piece other than the queen. A good reason for not choosing a queen is to avoid stalemate!
With few pieces on the board and only a king left for your opponent, you must be careful. Accidental stalemates are very common in these situations.
In examples 1 and 2 White can queen his pawn. Nice material profit! But… also a stalemate.
By promoting to another piece, White is heading for the win.
Take your time to study the examples and try to understand the differences between both positions.
In example 3 White can take the knight and safely promote to a queen. Black’s king cannot move and is not in check. However, it is not stalemate. Black still has a bishop that can move.
What do you have to do?
Find the best way to promote your pawn. Beware of stalemate!