The Announcements Forum
The Announcements forum is a special kind of discussion forum. It generally appears at the top of every Moodle course outline. Announcement forums are for instructor's to post class updates for students. Students cannot post messages or replies to messages in the Announcements forum.
In addition to appearing in the forum itself, recent messages posted in Announcements also appear in the "Latest Announcements" block on the right side of the course - as long as you haven't made that block hidden to students.
For posting messages within it, the Announcements forum works just like other Moodle forums. In the forum, click on the "Add discussion topic" to write your message.
Your messages will also be forwarded to the email connected to students' Moodle accounts - this is generally their SCC email.