What chain is IoTeX on?

Could you please elaborate on the underlying blockchain network utilized by IoTeX? Specifically, I'm inquiring about the technology stack, consensus mechanism, and any notable differences it might have compared to other major blockchains in the market. I'm curious to know how this particular choice impacts the performance, scalability, and security of IoTeX's ecosystem. Additionally, I'm interested in understanding the strategic reasons behind this decision and how it aligns with IoTeX's long-term vision and goals.