What is hashtag? When is it used?

[Megzz]

Why do people say hashtag blah blah blah? What does it mean and when is it used?

[Javier Gutierrez]

Its used in twitter its this sign #. They use it to help label there tweets.

[The]

It's the pound sign (#) and it's used popularly on twitter for trending topics.

[Zane]

hash tags allow ppl too search a tag and if you have used the hash tag they searched they can see your pictures and many other who tagged the same thing example #ootd means outfit of the day if you search that tag or click on someones tag you will go to a list full of picture of that tag via instagram

[≥Lilly≤]

Hashtag is a thing that is most commonly used on social media sites like Twitter and Instagram. When someone posts a status saying "Just came back from the beach! #beach #water #fun", the words in front of the # are automatically tagged. On Instagram, you could click on the hashtag "water" and see all the hashtagged photos that have been taken. You could really hashtag anything.
There really isn't a point for hashtags; a lot of people only use them to get more followers by hashtagging specific words.
For example, lets say I post a picture of a flower, then before I post it, I hashtag "flowers". Someone who might be interested in flowers might see the picture, then follow me if they like it. Get it?
It's all kind of a complicated, teenage girl reference that has taken over social media in a negative way, as people take it far too seriously.