Yes, charter schools can be a great opportunity for kids! Usually charter schools are run for what Americans call middle school and high school; usually grades 6-12 or sometimes 7-12. You may apply for your children to attend a charter school even if you don't live near or in the same "district" as the school.
Because charter schools are such a popular option, they can be difficult to get into. Many charter schools run a lottery and each year a certain number of children are randomly chosen to attend that school; think of the Green Card Lottery—it is the same idea! Make sure to apply for the “lottery” if you would like your children to attend a charter school but are having a difficult time getting him/her in.