One of the differences between the long-term scheduler and the short-term scheduler is:

The long-term scheduler, also known as the admission scheduler, is responsible for controlling the admission of processes to the system from the input queue. It decides which processes should be brought into the ready queue from the job pool. This scheduler is invoked less frequently as it manages the execution of programs that can take a long time to complete. Its main objective is to maintain a good mix of I/O-bound and CPU-bound processes.

On the other hand, the short-term scheduler, also known as the CPU scheduler, is responsible for deciding which process in the ready queue should be executed next by the CPU. This scheduler is invoked very frequently, usually on every clock tick, so it must be very fast. Its main objective is to increase system performance according to a specific algorithm, such as priority scheduling, round-robin scheduling, etc.

In summary, the main difference between the long-term scheduler and the short-term scheduler is their roles and frequency of invocation. The long-term scheduler controls the admission of processes to the system, while the short-term scheduler decides which process to execute next. The long-term scheduler is invoked less frequently, while the short-term scheduler is invoked very frequently.