What is the different usages of their, there, and they're

Their is possession, "thier toy"

There is like, over there "That tree looks pretty over there"

They're is like they are, "they're such nice people"

- "a.) it includes letters and books gathered over 1200 years, and consists of two parts.

- most of the new testament is letters from paul to the different churches, and since there's a new testament that means there is an old testament. "