The best distinction I have heard is that you lead people, and you manage things. People whose job title is manager might have to lead people too, but they're

The best distinction I have heard is that you lead people, and you manage things. People whose job title is manager might have to lead people too, but they're being held accountable for managing a thing. A project, a product, a budget, a release, a software system. Managing means 'making sure the thing happens'. What a staff+ engineer is held accountable for is engineering. What gets built and how. That a technical solution meets its requirements and constraints. In order to do that they might also need to lead people. But they don't have to manage anything.