What is zugzwang in chess? What is the zugzwang? I have read this term in chess book but the term not much clear to me. Anyone know to to use this and what are the advantage of this?
Here are some zugzwang positions which have been shown in answers to earlier threads:

4k3/8/3P1P/8/8/3p1p2/8/4K3 w - - 0 1


First to move loses (posted by GloriaVictis at this question on symmetrical zugzwangs).

8/8/8/3pK3/2kP4/8/8/8 w - - 0 1


The "trebuchet" (posted by Evargalo in the same thread).

3k4/3P4/4K3/8/8/8/8/8 w - - 0 1


Posted by Simon Louchart in this thread.

Here is a Q v RPP zugzwang: White to move can't win, but Black to move loses:

[Title "KQkrpp position from John Beasley's collection of zugzwang positions"]
[StartFlipped "0"]
[fen "kr6/1pK5/pQ6/8/8/8/8/8 b - - 0 1"]

1... Rc8 2. Kxc8 a5 3. Qxb7#


Seeing as a KBP v K position has been posted in another answer, here's an example of such a position which really is a zugzwang: White to move can't win, but Black to move loses:

[Title "KBPk position from John Beasley's collection of zugzwang positions"]
[StartFlipped "0"]
[fen "kB6/8/1PK5/8/8/8/8/8 b - - 0 1"]

1... Kxb8 2. b7 Ka7 3. Kc7 Ka6 4. b8=Q Ka5 5. Qb3 Ka6 6. Qa4#