Sprint spillover
Sprint work that isn't completed within the iteration and spills into the next, the per-sprint instance of carryover. Spillover is most often caused by stories that were too large, undiscovered dependencies, or interruptions; tracking which stories spill and why is far more useful than tracking how many points spilled in aggregate.
Sprint spillover, work that slips into the next sprint, is the same phenomenon as carryover, viewed from the sprint boundary. A small amount is healthy slack; a recurring pattern means the team is loading sprints past its real capacity or splitting stories too coarsely. The useful response is structural, tighten estimates, shrink stories, reserve buffer for interruptions, not a motivational push that just resets the cycle next sprint.