To come means to move toward the speaker or toward a place being talked about. When your mom calls “Come here!” she wants you to move to where she is. When a friend invites you to come to their birthday party, they're asking you to travel to wherever the party will be.

The opposite of come is go. You go away from where you are, but you come toward a destination. If you're at school and tell your parents “I'm coming home,” you mean you're heading toward home. But if you're at home and say “I'm going to school,” you're moving away from home toward school.

Come works differently depending on perspective. Imagine you're at a park and your friend is at home. Your friend might text you “Can I come to the park?” because they'd be moving toward where you are. From your point of view, you might say “Yes, come join me!” because they'd be moving toward you.

The word has dozens of other uses too. When something comes true, it happens. When an idea comes to mind, you think of it. When someone comes around to your way of thinking, they change their opinion. And when you finally understand a difficult math concept, you might say “Oh, now I get it! It's all coming together!”