If you're using
Twitter or
Instagram for example then you know how
#hashtags work. You add them to your posts in order to bundle those about certain topics. This week
Facebook is finally introducing hashtags as well. Using them is as easy as on Twitter or Instagram.
Check out the
#flatland hashtag on Facebook and
follow us while you are at it ;-)
It usually takes some time for Facebook to roll out new features like that to all users.