An assurance of availability for a quantity and quality of resources for a future time-point. If resources are unavailable at this point in time for a job, we reserve an allocation (physical resources) for that job in the future. There can be variance between how the reservation is done (e.g., very specific resources vs. matching a particular flavor) as well as guarantees, as different environments make different assumptions about resource availability. In an environment where there are essentially unlimited resources, a reservation may not be a relevant or widely used term.
Converged Computing Authors. "Reservation." Converged Computing Community Space 29 Nov 2024, https://converged-computing.org/docs/reservation/ (accessed 29 Nov 24). [doi]