Is BNB ERC-20 or BEP2?

Could you please clarify for me if BNB is an ERC-20 token or a BEP2 token? I've been trying to understand the differences between these two standards and how they apply to BNB specifically. As a crypto investor, it's important for me to be well-versed in these details, and I'm hoping you can provide some clarity. Could you also explain the significance of each token type and how they function within the blockchain ecosystem? Thank you for your assistance in this matter.