Anyone who has had a conversation about Twitter may have seen or heard illustrations like this:
What does that # mean? Well the #, or pound sign, symbol in the Twitter world is known as a hashtag. Putting this hashtag in front of a consecutive string of letters allows you to use that word or phrase as a category in a Twitter search. So you can do a search for “#in” on Twitter and every person who has tweeted and referenced “#in” in their tweet would show up on the search results.
You can also save that search within Twitter so that if it is a topic you want to follow, you can reach it easier.