Context switching is the mental shift from one task to another.
Each switch carries a switch cost: your brain must reconfigure goals and rules, which slows responses and raises errors.
After interruptions, part of your attention stays stuck on the previous task (attention residue), so performance on the next task dips until the old context fades.
Cluster similar tasks, protect uninterrupted focus blocks, batch meetings back-to-back, prefer asynchronous messages over reactive pings, mute non-urgent notifications or "park" stray thoughts in a capture list to minimize residue and resume faster.
Frequent switching fragments working memory, reduces depth and increases fatigue—so you feel busy but make slower progress.