Como funcionam as Exchanges de Bitcoin e criptomoedas?

How do Bitcoin and cryptocurrency exchanges function? Could you elaborate on the mechanisms and processes behind their operation? I'm particularly interested in understanding the role of liquidity providers, order matching, and how transactions are securely executed on these platforms. Additionally, I'd like to know about the regulatory frameworks that govern these exchanges and the measures they take to ensure the safety and security of user funds. Could you also discuss the challenges and risks associated with trading on such platforms?