Tagging helps other users and the community manager find your posts and questions to the community. In the MAP Growth & Formative Assessment communities, you'll want to tag any of your conversations with "chatter" or "backchannel" if you want these to be promoted in the Event Forums area at the top of the space.
Tagging is simple. Just scroll down to the bottom of your post and find the tag field. Add your tags, check their spelling*, and then post your question.
*Note that as you type suggested tags that you can select from will automatically appear.