What is CoinMarketCap and how to use it?

Could you please elaborate on what CoinMarketCap is and how one can effectively utilize its functionalities? I'm interested in understanding the role it plays in the cryptocurrency industry, the kind of data it provides, and any tips or tricks for getting the most out of this platform. Additionally, I'm curious about its reliability and whether it's a trusted source for crypto market insights. Would you be able to shed some light on these points? Thank you for your assistance.