Oftentimes, it is assumed that online learning takes place exclusively online, however there are three different formats in which online learning occurs. Those formats are: 

Supplemental: The primary format for learning occurs in a face-to-face classroom, course materials and learning materials are often posted on a classroom Web site to supplement classroom instruction.

Blended: The primary format for learning occurs both face-to-face and in an online classroom. Learning materials and content are often distributed online.

Exclusive: The primary format for learning occurs in an online format only. All learning content, materials, and interaction occur through the online classroom.