Forums are quite common in ILIAS or Moodle. Forums have the advantage that all students have the same level of information and they can substitute seminar discussions, for example.
In forums, posts are presented hierarchically in so-called threads (in ILIAS these are called “topics”). This makes it easy to see which posting (= forum post) relates to which subject.
Before creating a new thread, please always check whether you can find the topic in an existing thread.
Conversely, make sure to open a new thread for a new topic and not simply to "hijack" an existing thread.
Pay attention to politeness in forum discussions, too!