'Its' is a possessive pronoun. It means that it shows the ownership of something. Unlike 'his' or 'hers', it is not gendered therefore it can refer to a non-human or non-gendered human's possession.
- The dog loves its new toy.
The word 'it's' is the contraction of two words, 'it' and 'is' or 'has'. Whenever someone wants to say 'it is' or 'it has', 'it's can be used.
- I love pizza. It's very tasty. (It is very tasty.)
- It's got to be a joke. (It has got to be a joke.)
There is a confusion because apostrophes are used to show possession.
- The cat's paw.
But it does not mean that the possession of 'it' is 'it's'