Discussion boards allow students and instructors to communicate with one another asynchronously.
Instructors frequently use the Discussion Board as a communication tool for courses. Each main posting in the Discussion Board is called a “forum”. Related replies are called “threads”. Depending on how your instructor chooses to set up the discussions, students might be able to start new threads and reply to existing threads in a forum.
For detailed instructions on how students can use discussions, please visit Discussions at Blackboard Help.