Well, if you want a much more in-depth discussion (at least if you follow the links...) with examples than Wikipedia, you could do a lot worse than checking tvtropes.org.[1]
P.S. Sorry in advance for the loss in productivity to anyone that clicks though and doesn't know what they're in for...
P.S. Sorry in advance for the loss in productivity to anyone that clicks though and doesn't know what they're in for...
1: https://tvtropes.org/pmwiki/pmwiki.php/Main/ChekhovsGun