It is a pronoun. A pronoun replaces another word so that you do not repeat the same word too many times.
1. Look back to the pronoun it in the first paragraph.
3. How many times do you see the pronoun it?
4. What does the pronoun it replace?
Use the pronoun it for singular words. Use the pronoun them for plural words.
Example: Kaldi took care of his goats. He watched them while they were eating some plants.