According to Vitalik Buterin, Multi-Party Computation (MPC) typically operates as N/2-of-N or N/3 or 2N/3, involving a committee trusted by a large user base. In contrast, Two-Party Computation (2PC) involves two parties combining their private inputs in a trustless manner, ensuring that neither party can extract the other's data. This distinction is crucial for understanding different security models in cryptocurrency transactions.