Yeah, echoing @AnnaLandin; I feel like foreshadowing is a really broad idea! Like, foreshadowing can be the hints that won't make sense until it all comes together, or the symbolic clues of what's to come, but it can also be as simple as "okay I need to let the audience see hints that this villain is dangerous and itching to fight so that when the heroes encounter him, the fight won't feel random and out of the blue."
Foreshadowing is often a practical thing, making sure your audience has the information that they'll need. If you have a character who's gonna, idk, abandon the team at a crucial moment, you gotta foreshadow that! Because when it happens, you want the audience to think "oh no, of course, she sounded so frustrated with the team, of course she's leaving now!!" and not "wtf? why is she leaving." Foreshadowing her change of heart isn't just for fun, it's vital for the story to work!
Foreshadowing can also apply to tone or themes -- like, hinting at unsettling rumours in the innocuous opening of a story so that the sudden dark turn later on is intriguing and builds on growing fears, rather than just giving you confused mood whiplash.
Basically "foreshadowing" covers a whole bunch of important things that lots of stories need!