Sure. I'll try to concisely bring this to life.
A social impact bond is a new partnership agreement between government and a non-profit organization, and this agreement is based on the covenant that the organization will deliver on an outcome that government seeks to achieve. It's a way in which we can start to shift our thinking towards results, or what I'm calling an outcome, versus the activities or the inputs/outputs of a social intervention.
Because non-profit organizations do not want to take the risk of potentially failing and because they don't want to take the operational risk of delivering that program without that funding, they seek out investors to provide that working capital. The social impact bond is just a unique way to classify this new partnership agreement, whereby private investors put up upfront money to deliver a social program that is intended to generate better outcomes.