In a course room, you will see all the content that teachers have put there and you'll have access to, such as

• Documents
• Study material
• Assignments
• Tests
• Discussion Forum
• Links
• Video
• Surveys
• Schedule

When you answer e.g. in a forum, you write in an Editor. You can see more features in the editor if you click on the small box (1).

You can also enlarge the window if you are going to write much (2).