Coaches send thousands of camp invites. They typically cast a very wide net.
Camps are sources of revenue for the coaches and school.
Great advice we found here was to put sons' college lists together subjectively based on the intersection of where sons could play and where they could get admitted. Generally you need some outside help for that (e.g., scouts, coaches, guidance counselors) as we parents tend to think very highly of our kids' capabilities.
Once you have your list of schools (we did 25 initially), then your player needs to get in front of the coaches from those schools. This is true whether they've "invited" you to a camp or showcase or tournament or whatever...or not. You communicate to them. And you go where they are.
If your player is being actively recruited by a school, you'll most likely know it. Otherwise, your player is on a mailing list that tends to be very large.