Second person pronouns are used to talk about the person you are speaking to. These include you, yours, yourself, etc. You can be both singular and plural in English.
Third person pronouns are used to talk about people who are not either the speaker or the listener. They include the third person singular pronouns (like he, she, it) and third person singular pronouns (like they, them, etc.)
When we use third person pronouns, we often distinguish between genders. For example, she, her, and hers are often used to talk about women, and he, him, and his are often used to talk about men. They, them, and their can be used as gender-neutral pronouns. We can use these either because we don’t want or need to specify a gender, or because someone prefers non-gendered pronouns.
For inanimate objects—things that are not people—we use it, its, and itself.