Second-person narration is when the speaker talks directly to the reader, using pronouns such as “you” and “your”.
Third-person is when the speaker tells the story in a completely detached manner, without using “I” or “you”. They aren’t involved; they just tell what happens. There are two types of this: limited, when they don’t know what’s happening in every character’s mind, and omniscient, all-knowing, where they do tell what each character is thinking.