When a piece is pinned, it cannot move without exposing a more valuable piece or the king. This makes it an ideal target—build pressure on the pinned piece with additional attackers until your opponent can no longer defend it, winning material or gaining a decisive advantage.
Example 1:

The bishop on d4 is pinned to White's queen. How can we take advantage of it? We should attack it - 1...e5! and White loses his bishop as moving it would give up a whole queen!
Example 2:

If you chose the natural 1...Rd8, you made a mistake!


The correct way was 1...Ra7! since after 2.Rxa7

We can simply take White's queen: 2...Qxb5! - we are not getting mated along the back rank since we have Kh7 after Ra8.