A contest can be configured to use one of the two queue types for submissions: shared or dedicated.
A shared queue will process a submission only when the dedicated queue is empty. In other words, submissions in a dedicated queue will always have a higher priority.
A shared queue processes one test case at a time for each running submission.
Note that not only submissions, but compilations and test runs from the code panel also take positions in these queues.
Training contests use a shared queue for submissions.
If there are no overlapping contests, then a shared queue is usually capable of handling submissions from around 20 participants.
A dedicated queue, on the other hand, can be scaled to accomodate contests of any size. This is offered as a part of our Standard and Prestige tier contests.
A dedicated queue processes multiple test cases in parallel for each running submission.
