There is a lot of confusion between it's and its but if you know the details about their usage, you will know that there a good reason for the confusion. So what is the difference between the two?
It's - this is short for 'It is' or 'It has'. It cannot be used for anything else. If 'it's' cannot be replaced by 'it is' or 'it has' then it is incorrect. They call it the 100% rule.
E. g. It's been raining for a week (this can also be written as - it has been raining for a week)
Its - this is like using his or her, only that his is masculine, her is feminine, 'its' is used for neutral purpose.
E. g. The company has its own views in this matter.
It's a pretty simple rule, isn't it?