Reddit communities, known as subreddits, are specialized forums within the Reddit platform where users can discuss specific topics. Each subreddit is identified by a unique name, often prefixed with "r/", such as r/science or r/movies. Users can post content, ask questions, and share information related to the community's focus. Members of a subreddit can upvote or downvote posts and comments, influencing their visibility. This voting system helps surface popular content while allowing users to engage in discussions. Subreddits can range from broad topics to niche interests, catering to diverse audiences and fostering unique online communities.