What Blockchain is STX on?

Could you please explain to me the blockchain technology that STX is utilizing? I'm quite curious about the underlying framework that supports this cryptocurrency. Could you elaborate on the specifics of the blockchain, such as its architecture, consensus mechanisms, and any unique features that make it stand out? Additionally, how does the STX blockchain ensure security and scalability? I'm eager to understand the technological backbone behind this cryptocurrency and how it contributes to its overall functionality and performance.