There are a variety of choice options in public education in Colorado. Probably the clearest term is "charter" because it means that there is a contract with an authorizer, usually a local school district. However, if that district doesn't have exclusive chartering authority then the charter could be from the state Charter School Institute.
One school district uses the terms, "internal charter" and "external charter." Another district calls their choice school a "district charter" that is really not a charter school at all. Still another district contracts with a private school for only some grade levels offered by the school. The reason there is such a variety of terms, and definitions of choice schools, is because we're a "local control" state. This means local school districts have the Constitutional authority to establish their own curriculum and operate their districts.
Here are the terms used for choice schools and a short definition:
* Contract: a district school; could be operated very similar to a charter school or could be certain grade levels of a private school
* Magnet/Option: a district-operated choice school with a specific mission, such as a school for performing arts, which requires an audition prior to enrollment
* Focus: a district-operated school with a specific mission; could be a math/science focus; could be a neighborhood school