What does BFF mean? (Internet slang)

What is Internet Slang?
Internet slang (Internet shorthand, Cyber-slang, netspeak, or chatspeak) refers to a variety of slang languages used by different people on the Internet.
There are various types of internet slang including letter homophones (u r gd), punctuation (!?), capitalization (STOP!), onomatopoeic (hahaha) and emoticons (=]).
Why Internet Slang are Used?
Internet slang are created for typing long sentence or words in less time Internet slang are commonly used in chat, Internet, social sites,  websites that have online communitys such as forum boards or community irc lines. Such words often containe 3 letter, (a common patern noticed)
The Meaning of BFF in Internet Slang
BFF means "Best friends forever"
So now you know - BFF means "Best friends forever"