it's

contraction4

1. •
   (dialect, nonstandard) a short form that says that something exists or is in a place, meaning "there is" or "there are"

   • It's a package for you by the door.
2. •
   a short form of "it is"
3. •
   a short form of "it has", used before another verb such as "been" or "got"

   • It’s been a long time since I’ve had cheesecake.
4. •
   (nonstandard) Contraction of it + was.

   • When I was a kid, it's the thought that counted but, now, it's all about the Benjamins.