It's is a contraction and should be used where a sentence would normally read "it is" or "it has." The apostrophe indicates that part of a word has been removed. Its with no apostrophe, on the other hand, is the possessive word, like "his" and "her," for nouns without gender.

Its is a possessive form of the pronoun it, meaning belonging to it. It’s is a contraction of the words it is or it has. (Interestingly, we don’t really contract it was into it’s.) If you’re trying to figure out whether you should write it’s or its, swap in it is or it has. If the sentence makes sense with either of those substitutions, use it’s.

Its and it’s are homonyms (words that are pronounced the same), but they have different meanings. Its is the possessive form of it and means “belonging to it.” It’s is a contraction of “it has” or “it is.” Its’ (with an apostrophe at the end) is often mistakenly used in place of its, but it is not actually a word.

Its (without an apostrophe) is the possessive form of it, so it means ‘belonging to it’. It’s (with an apostrophe ‘s’) is a contraction (shortened form) of it is or it has. Its’ (apostrophe after the ‘s’) is not actually a word, even though people sometimes mistakenly use it in place of its.

However, "its" (without an apostrophe) is a possessive pronoun, like his or her. " It's" (with an apostrophe in front of the "s") is a contraction of "it is" or "it has." The apostrophe in "it's" is a mark of omission, not possession.