Context switching is a technique used by operating systems to manage multiple processes on a single CPU, allowing them to run smoothly without blocking each other. It involves saving the state of the current process and restoring the state of the next process to be executed, which is stored in a Process Control Block (PCB). This process helps share the CPU among multiple processes, handle interrupts, and manage input/output requests, ensuring that high-priority tasks are executed while others wait their turn. While context switching allows multitasking, it introduces overhead due to the time spent saving and loading process states instead of executing tasks. To reduce this overhead, minimizing active processes, using faster hardware, and improving process scheduling strategies can be beneficial.