How does Robinhood Crypto work?

As a curious investor in the crypto sphere, I'm intrigued by Robinhood Crypto's unique offering. Could you explain, in layman's terms, how does Robinhood Crypto actually work? I've heard it's a mobile-first platform that allows users to buy, sell, and trade cryptocurrencies with ease. But what's the underlying mechanism? How does Robinhood ensure security for its users' digital assets? And how does it compare to other crypto exchanges in terms of fees, user experience, and supported cryptocurrencies? I'd appreciate a concise yet comprehensive overview of Robinhood Crypto's operations.