it's

About 0.05 uses per million words.

Meaning

contraction Contraction of it +‎ is.
it’s too expensive; it’s coming right for us!; it's a free country
contraction Contraction of it +‎ has.
It’s been a long time since I’ve had cheesecake.
contraction Contraction of it +‎ was.
When I was a kid, it's the thought that counted but, now, it's all about the Benjamins.
contraction There's, there is; there're, there are.
It's a package for you by the door.
determiner Obsolete form of its.
determiner Misspelling of its.