A philosophical zombie is a thought experiment - that means it's an imaginary situation that people like to think about. It might sound weird, but it's meant to help us think about some tricky questions.
A philosophical zombie is someone just like you, except they don't feel anything. They don't feel tired, happy, sad, hungry, or anything else. It's like walking around with a robot. Everything looks and acts the same, but there's nothing inside.
People think about philosophical zombies to help them think about what makes a person real or alive - like emotions and feelings. Some people might think that a philosophical zombie is like a real person, except without any emotions or feelings. It's really an exercise to help us understand life, consciousness, and what might make us different from robots.