First time poster (new to worldbuilding). What are “magic” systems like in other people’s worlds, and why are they like that?

Hey all, new to the sub (and fairly new to worldbuilding). I’ve been doing this for two or three months, and I’m still figuring out how to add magic to my world.<br><br>I’m curious what kinds of magic systems other people have created, and why they designed them that way. What mechanics do you use to govern magic, and why did you choose them? What are the benefits and drawbacks to magic in your world, and why did you choose those? How does magic shape the world?<br><br>Thanks in advance, I’d love to hear about your worlds.