Watchable means that a video has passed through YouTube's filters that applied to education accounts. – Adults and students have access.

Video not approved for knoxschools.org means that content in the video does not adhere to YouTube's standards for education accounts. – Adults only have access.

Approve is an option given to adults in the education account to make a video available when YouTube deemed it not watchable. – Adults and students have access.

Video approved for knoxschools.org indicates that an adult in the education account clicked Approve to make the video available to students. – Adults and students have access.