the previous answer has answered this question adequately but i’d like to expand a bit on the explanation to distinguish the differences.

I, We, They, You, and He are pronouns, subject pronouns to be precise. to elaborate, subject pronouns are always used to describe who performs the action in a sentence (i.e “He asked this question”)

whereas Me, Us, Them, You, and Him are object pronouns. object pronouns are the opposite of subject pronouns. they occupy the role of who experiences the result/consequence of the action in a sentence (i.e I answered Him)

as a bonus, in addition to those two, we have possessive pronouns. this type of pronoun signifies, as the name implies, possession of something in a sentence. its presence asserts who owns something (i.e His question has been answered)

similarly,

Who is a subject pronoun (Who asked this question?)

Whom is an object pronoun (Whom did you answer?)

and lastly, Whose is a possessive pronoun (Whose question has been answered?)

i hope my explanation has satisfied your question and enlightened your knowledge on pronouns.