What is a crypto CFD & how does it work?

Could you elaborate on what a crypto CFD is and how it operates in the realm of cryptocurrency trading? I'm curious to understand how these financial instruments allow investors to gain exposure to the crypto market without directly owning the underlying assets. Specifically, I'd like to know if they offer leverage, how profits and losses are calculated, and the potential risks involved in trading crypto CFDs. Additionally, I'm interested in understanding the differences between trading crypto CFDs and purchasing cryptocurrencies directly.