what is meaning of hashtag #?

[Lauren]

A hash tag can be used, for example, to add a little saying on the end of a status/update on online, mainly social media websites. For example:

you can put your mood in a hash tag:

"I've had a really good day today #happy"

or you can write about a TV show you're watching:

"this show is so funny tonight! #hollyoaks #E4channel"

Basically, you can hash tag whatever you wish. A good tip is to make it short a sweet though, or else it can be a pain to work out what it actually says.