What is the difference between XSP and SPY trading?

Excuse me, could you please clarify the distinction between trading XSP and SPY? As I understand, both are financial instruments, but I'm unsure of the specifics that set them apart. Could you elaborate on their primary differences, including their underlying assets, trading mechanisms, and perhaps even their risk profiles? I'm eager to gain a better understanding of how these two compare in the broader context of the financial markets.