When a student enters a general purpose forum, they see the description entered during the creation of the forum, as shown in the following screenshot:

While writing a forum post, the student uses the same online editor you see when creating web pages, resources, and activities in Moodle.

Also, you can allow students to upload files to a forum posting. These files are attached to the forum post.

If you ask students to collaborate on assignments or ask them to review each others' work, consider adding a forum specifically to discuss the assignment. Encourage students to use the forum to preview each others' work and collaborate on various assignments.