…ution,” when Medium looks at your post and decides whether it meets their curation criteria or not. This can be tough to achieve as it’s very subjective, and the curators don’t typically give feedback. However, if you manage this, you know that your story will be recommended to be read by people who are interested in the topics you write in.
Medium actually just talked about this in a support email about the recent issues with distribution. Pretty much the system is broken and the stats on curation can’t be trusted because they are working on a new distribution system.