Twitter is a social media platform that allows users to share short messages called tweets. Tweets can include text, photos, videos and links, and can be replied to or shared by other users. By following other accounts, users see tweets from those accounts on their Twitter home page or feed. Hashtags allow tweets about certain topics to be found more easily. Businesses and organizations use Twitter to engage with customers and share information. With over 400 million tweets sent per day, Twitter is a widely used platform for communication and discovery.