What is the meaning of Catch-22?

Answer 1

The meaning of catch-22 is a logical contradiction that stops something happening, in particular when bureaucracy gets in the way of things being achieved.

The phrase comes from the book "Catch-22": a novel by Joseph Heller, in which Catch-22 was the catch caused by contradictory rules: You are not required to fly dangerous missions if you are crazy; It is sane to not want to do something dangerous; if you do agree to do something dangerous you must be crazy; only a sane person would ask not to do something dangerous.

So if you ask not to do a dangerous mission because it would be crazy, you are being rational and therefore still required to do it.