Its vs. It’s
Its is known as a possessive pronoun because it’s used as a substitute for a more specific thing that possesses something else. It is different from it’s, which is a contraction meaning it is. Notice these correct uses of the above terms:
◊ The cat is wagging its tail.
◊ It’s a shame that you can’t join us.
◊ It sounded like a wonderful story, but I could not follow its meaning.
◊ When you start receiving a higher volume of junk email, it’s probably time to consider a stronger filter.
Here are some other possessive pronouns:
my
his
her/hers
you/yours
our/ours
their/theirs