Twitter is a microblogging and social media platform that allows users to post messages of up to 280 characters known as tweets. It can be used for one-to-one, one-to-many, and many-to-one communication. For businesses, Twitter allows finding and engaging with customers and influencers by following industry experts, participating in relevant conversations, and establishing thought leadership in your field through concise posts. Tools like Hootsuite, Buffer, and TweetDeck help businesses manage their Twitter presence by scheduling posts, analyzing metrics, and monitoring conversations.