In the preceding example one is the antecedent of it.
There are several kinds of pronouns: personal, relative, interrogative, demonstrative, and indefinite.

PERSONAL PRONOUNS

I, me he, him it they, them
you she, her we, us

POSSESSIVE FORMS OF THE PERSONAL PRONOUNS

my, mine his its their, theirs
your, yours her, hers our, ours

Some of the possessive forms-my, your, his, its, our, their- are used before a noun in the same way adjectives are used to limit the meaning of a noun: my parents, your home, his coat, etc. They are possessive pronounce functioning as adjectives. Some people prefer to call these pronouns possessive adjectives.

REFLEXIVE AND INTENSIVE PRONOUNS

myself ourselves
yourself yourselves
himself, herself, itself themselves

Personal pronouns combined with –self, -selves may be used in two ways:
1. They may be used reflexively.
Barry hurt himself.
2.