Personal pronouns in English are I, you, he, she, it, we, you, they (nominative) and me, you, him, her, us, you, them (object pronouns). But why they are called personal pronouns? They are called personal pronouns to distinguish them from other pronouns, for instance demonstrative pronouns, relative pronouns, possessive pronouns, etc. etc.. All these pronouns represent a noun.
Example
possessive pronouns
This is Peters car.
It is his car.
demonstrative pronouns
This is Peters car.
This is his car.
relative pronouns
This is the car, which belongs to Peter.
All the pronouns mentioned above (possessive pronouns, demonstrative pronouns, relative pronouns) represent a noun. 'His' substitutes Peter, 'this' substitutes the car and 'which' substitutes the car. But beside the function to represent a noun, they have another function. They indicate to whom something belongs (his), point to something (this) or establish a relationship between a relative clause and an element of the main clause. That' s what they distinguish from personal pronouns. A personal pronoun only represents something, that' s his only function, it does nothing but that.
Overview
1st person singular
io
I
2nd person singular
tu
you
3rd person singular masculin
lui
he
3rd person singular feminine
lei
she
1st person plural
noi
we
2nd person plural
voi
you
3rd person plural
loro
they
There is no Italian word for 'it', so there is no neutral noun that needs to be represented by a personal pronoun.
