How does Crytpo work?

Could you please explain to me how does Cryptocurrency actually work? I'm really curious about the underlying technology and mechanisms that make it possible for digital coins to exist and function in our world. What exactly is blockchain and how does it secure transactions? How are cryptocurrencies created, and how do people trade them? I've heard about mining but I'm not quite sure how it fits into the picture. Could you clarify these points for me in a simple and understandable way?