Twitter lets people post information snippets to a platform where they’re visible and searchable by anyone else in the world. These information snippets include short text messages, (140 characters, to be specific) as well as web links, pictures, and videos. A piece of information posted on Twitter is called a “tweet”.
Everyone who posts to Twitter has their own unique Twitter username that starts with the “@” symbol: @janedoe, for example. Everything a person posts is marked as having come from their username.
If you’re interested what another person has to say, a thought leader, a newsmaker, or just a friend, for example, you can follow that person so that their tweets will show up in a list of tweets that Twitter presents to you. This list is called your timeline.
If you want to respond to something another person has said, you can reply to their post with your own post. A reply post begins with the @username of the person you’re replying to.
Tweets will often include “hashtags”. A hashtag is a short string of characters that begin with the “#” symbol: #TakeYourKidToWorkDay, for example. Hashtags let people tie their tweets to common topics or ideas.
Twitter is a window on what’s happening and what news and thoughts are trending around the world.
As a business, Twitter makes money in two ways:
It sells access to its full feed of tweets to companies like Google and Microsoft that want to use it in their own news feeds and searches.
It allows advertisers to post “promoted” tweets. Promoted tweets will show up in the timelines of users that Twitter has determined will likely be interested in those tweets.