Reddit is a social media platform and online community where registered users can submit content, such as text posts, links, images, and videos, to various topic-based communities known as "subreddits." These subreddits cover a wide range of interests and topics, including news, entertainment, technology, science, sports, gaming, art, and many others.

Users can participate in discussions by commenting on posts, upvoting or downvoting content, and engaging with other community members. Reddit's structure allows for the formation of diverse communities with their own rules and moderation, which helps maintain the quality and integrity of each subreddit.

The platform uses a voting system to determine the visibility of posts and comments. Upvoting a post or comment increases its visibility, while downvoting decreases it. This system aims to surface the most relevant and interesting content to the top while pushing less valuable content down.

Reddit also offers features such as user profiles, private messaging, and the ability to create and moderate your own subreddit. It has become a popular platform for sharing news, memes, asking questions, seeking advice, and engaging in discussions on a wide range of topics.

It's worth noting that since my knowledge is based on information available up until September 2021, there may have been updates and changes to Reddit's features and policies beyond that point.