Online learning in K-12 schools refers to distance education where teachers and students are separated by time or space. It can take various forms including online, video-based, or print-based independent study. There are different types of K-12 online learning programs including statewide online learning, online learning consortia, programs through colleges and universities, cyber charters, and local school district programs. Critical success factors for online learning include clear expectations, meaningful curriculum, opportunities for collaboration, and teacher quality.