What is opBNB mainnet?

Could you please explain what the opBNB mainnet actually is? I've heard about it in the context of blockchain technology and cryptocurrencies, but I'm not quite sure what its core functionalities and significance are. Is it a platform for transactions? A network for developing decentralized applications? Or perhaps something else entirely? Could you elaborate on its features, benefits, and how it differs from other blockchain networks? Thank you for clarifying this for me.