What is an hash tag? please help?

[Kenneth Angelo]

What is a freaking hashtag

[Keith]

This is a hash tag.

[Benoy]

Hashtags provide a means of grouping such messages, since one can search for the hashtag and get the set of messages that contain it.

[Good]

a hash tag (#) is used in Twitter and Instagram as a sort of 'Tagging' for instance
"Went skydiving today #Awesome #wanttodoitagain"
when i say its like tagging i mean tagging it to another page. they are mostly used to add on to the end of a post so people can get a better feel for what the person is feeling about their post.
Hope this helped