Context switching is the process of saving the state of a currently running process and loading the state of the next process to be executed. This allows multiple processes to share the CPU efficiently.

Context Switching is the process of saving and restoring the state (or context) of a process or thread during execution, so that multiple processes can share a single CPU resource. Formally, context switching is defined as the act of storing the values of the registers, program counter, and other state information of the currently executing process, and restoring the context of another process to resume its execution. Context switching allows the operating system to implement multitasking, although it introduces some overhead.

During a context switch, the operating system saves the current process’s CPU registers, program counter, and other state information in the process’s PCB (Process Control Block). It then loads the next process’s state information from its PCB.

Although necessary for multitasking, context switching introduces overhead because the CPU spends time saving and restoring states instead of executing actual instructions. Minimizing this overhead is a key design consideration for modern operating systems.