What name does Reddit use for its subject-based communities?

Reddit uses the name “subreddits” for its subject-based communities.

A subreddit is a user-created discussion area organized around a topic, interest, activity, identity, or purpose. Reddit now also officially describes subreddits as “communities,” but “subreddit” remains the platform’s distinctive and widely recognized term. The word combines “Reddit” with the prefix “sub-,” suggesting a smaller community within the larger service.

Each subreddit has its own name, moderators, rules, and culture. Members can submit posts, comment on discussions, and vote on content; those votes help determine what becomes more visible. Examples include r/science for scientific topics and r/gaming for video games.

A common mix-up is treating a subreddit as just a single discussion thread. A subreddit is the whole community, while a post or thread is one conversation inside it. Subreddit names normally begin with “r/,” whereas Reddit usernames use “u/.”