Reddit is an American social news aggregation, content rating, and discussion website. Registered users submit content to the site such as links, text posts, images, and videos, which are then voted up or down by other members. Posts are organized by subject into user-created boards called "communities" or "subreddits". Submissions with more upvotes appear towards the top of their subreddit and, if they receive enough upvotes, ultimately on the site's front page. Reddit administrators moderate the communities. Moderation is also conducted by community-specific moderators, who are not Reddit employees. As of December 2022, Reddit ranks as the 20th-most-visited website in the world and 6th most-visited website in the U.S., according to Semrush. About 42–49.3% of its user base comes from the United States, followed by the United Kingdom at 7.9–8.2% and Canada at 5.2–7.8%.