its ... or ...
it's ... ?
Don't take this too seriously, but ...
I see this error quite a lot actually ... and made even by very intelligent and educated people who write well (even more intelligent and educated than me). And not even dyslexic.
Please ... if you love me just one bit ... consider that sometimes that apostrophe means something. I assure you it does. It's needed for contractions. But when it comes to indicating possession of something/someone, don't add that apostrophe ... because that's called grammar abuse.
Therefore:
it's = it is or it has (depending on the context)
and
its = possessive pronoun (for example, "This dog is very loyal to its owner")
It's very easy to differentiate between the two. Just remember the apostrophe has its own use in this case.
Free lesson over.