If a pawn reaches the other side of the board it can turn into any piece. There's almost no reason to get anything other than a queen though so that's what everyone always takes.
Only exceptions are cases where queening the pawn leaves the opponent with no valid moves but not in check, i.e. stalemate. That's somewhat rare but it is important to watch out for. Sometimes you need to promote to bishop or rook instead.
100% true. In fact, there are even more situations where promoting to a knight is useful, since it can help you keep tempo if you're simultaneously gaining material and keeping the opponent in check.
If a pawn reaches the other side of the board it can turn into any piece. There's almost no reason to get anything other than a queen though so that's what everyone always takes.
Only exceptions are cases where queening the pawn leaves the opponent with no valid moves but not in check, i.e. stalemate. That's somewhat rare but it is important to watch out for. Sometimes you need to promote to bishop or rook instead.
There are also conceivable situations where you would want to promote to a knight, since all the spaces the knight sees are spaces the queen can't.
100% true. In fact, there are even more situations where promoting to a knight is useful, since it can help you keep tempo if you're simultaneously gaining material and keeping the opponent in check.