what does this mean?Im so lost.?

[haha!!!]

on facebook I've seen so many people put #jerkflow they didn't actually put jerkflow but they have the number sign and something behind it...below are some examples of what I mean.

#hungry
#badazz
#jerkflow
#swagger jacked
#idiot
and etc

what does it all mean?

[haha!!!]

i had no clue up til like a week ago hahaha! kay so like
when u put the "#" u make whatever u put after it a hashtag
so u know what a trending topic is? thats what they wanna make it
or theyre just doing it or fun