What is the difference between Binance Chain and Binance Smart Chain?

As a cryptocurrency enthusiast, I'm curious to understand the nuances between Binance Chain and Binance Smart Chain. Could you elaborate on the key differences between the two? I've heard Binance Chain is focused on high-speed transactions, while Binance Smart Chain aims for broader smart contract functionality. But what are the technical distinctions? How do they differ in terms of scalability, security, and adoption? Also, what types of decentralized applications (DApps) are most suited for each chain? I'd appreciate a concise yet comprehensive breakdown.