Gith is another word for "right," as in "correct." It replaced these words mainly because it is easier to type. May have originated from a typo the same way as common words such as teh or pwn.
JohnTheManNinja: ya steve, maybe ur gith afterall.
SteveO: well I am teh cool, jeez bro.
GitHub is a website popular with programmers because they can publish their programs there and work with other people on the internet to help make the code even better. One feature is that people can fork code, which means that they can essentially copy the code and make whatever changes to it that they want without editing the actual code. It's kind of like a group project where people can do whatever they want.
An absolutely foolproof way to keep minors from viewing content deemed "too mature" for them to watch.
Billy: "So I was trying to watch some videos for an M rated game, and I ran into an age gate, so I put in my real birthday. SOMEHOW it managed to figure out that I am 12. CURSE YOU AGE GATE!!!"
Bill: "Fucking age gate! *quick scroll* THERE! I was born on January 1, 1904. Fuck you age gate."