Twitter is a social media platform that allows users to post short messages called tweets. The key aspects of using Twitter include:
1. Finding other users to follow to receive their tweets and engage with their content.
2. Composing tweets of 140 characters or less that will be posted to your followers' feeds.
3. Mentioning other users with an @ symbol to contact or include them in tweets. Hashtags can also be used to categorize tweets.
4. Direct messaging allows private communication between users who follow each other. Trending topics show popular topics being discussed and the search function allows finding specific content.