What kind of a pronoun is it?

The pronoun 'it' is a personal pronoun, a word that takes the place of a singular noun for a thing.

The pronoun 'it' functions as a subject or an object in a sentence.

Examples:

Mom made a chocolate cake for my birthday. It is my favorite. (the pronoun 'it' takes the place of the noun 'chocolate cake' as the subject of the second sentence)

You may borrow the book. I think you will like it. (the pronoun 'it' takes the place of the noun 'book' as the direct object of the verb 'will like')