The core difference between IT staff augmentation and managed services (also known as outsourcing) lies in the final project outcome. IT staff augmentation is the utilization of the professionals that augment your internal house development team and perform some specific assignments on a temporary basis outside your organization.
With IT staff augmentation, you receive the required tech resources and expertise with their committed working hours. On the other hand, the whole management process is on your side. Basically, IT staff augmentation is used by those who are interested in outsourcing a specific tech task and/or functionality. The outsourcing model is a provision of IT outsourcing services focused completely on the solution, problem, or project basis.