When you hire an external resource to accomplish a specific, limited-scope IT project within a given period of time, that’s called IT project outsourcing. It might include the development of products, services or solutions and involve multiple parties within and outside of your organization.
Some IT projects that are typically outsourced are migration from an on premise service to the cloud, migrating email from G-Suite to Microsoft 365 or integrating multiple systems together.
Internal IT teams usually don’t have the expertise or bandwidth to take on the project. Some managed service providers also offer IT project outsourcing while others only complete IT projects for existing managed IT clients.