What does this mean on twitter?

[Gem]

#hashtag is used to tag words so it makes the word clickable, therefore if people click this or yourself can see what others have said about the same thing quickly.
Its mainly used to set "Trends" if you look on your homepage it says Worldwide trends & this is mostly words people have Hashtagged.

so say if theres somthing on tv about say simon cowell, people will #Simoncowell and say what they want to say

i have never seen FF used before but by searching on google it says Follow Friday. guessing people follow each other and follow back on fridays?
lol.


will follow you!