Charter schools??

Excuse my ignorance here, I grew up in rural Alabama and have no clue what a charter school is or how they work.

We are moving to a different state and will be living closer to (or in) the city. I’ve been looking at apartments and of course my biggest thing is finding a home that has a good school.

However all of the assigned schools seem to be rated 4/10 or lower on greatschools.org

But the charter schools are 8/10 or higher.

So are charter schools private schools?

(We’re moving to Charleston,Sc if that helps anyone)