https://www.cnet.com/news/avengers-infinity-war-after-credits-scene-what-does-it-mean/

Warning: I'll be spoil the after-credits scene in Avengers: Infinity War below, and the ending of the movie too. Leave right now if you don't want to know what happens before you see the movie. Good? Good.

Ever since Nick Fury showed up at the end of Iron Man a decade ago, the Marvel post-credits scenes have served to give exciting peeks at the future of Earth's Mightiest Heroes. Fast-forward 10 years and 18 other movies, and the tradition continues with Avengers: Infinity War.