Its is a possessive determiner we use to say that something belongs to or refers to something.
He doesn’t think its a good idea to spend all his money on video games.
He doesn’t think it’s (it is) a good idea to spend all his money on video games.
Its been a year since the last time they met.
It’s (It has) been a year since the last time they met.
The computer looked as though it’s power supply had failed.
The computer looked as though its power supply had failed.
A car is no good without it’s wheels.
A car is no good without its wheels.