IDK! but I like it!

'1. How Processes Context Switch saves "Program Counter" and "Stack Pointer" of interrupted process (program) when interrupt happened and before it begin Interrupt handling code at Kernel mode. Interrupts aka Traps.

'2. Interrupt-Based Context Switching - mostly it's software responsible for context switching by interrupt handling code in OS.

'3. Multiple Register Sets - 2 "Context Register sets" in CPU. First sets for "User mode" processes and Second sets for "Kernel mode" process and it can get access to "User mode" sets. But it's unpopular CPU architecture.

'4. Hardware-Assisted Switching: Hardware-Assisted Stack Management and Hardware Task Switching.

'5. Hardware-Assisted Stack Management - Interruption Handling code or the code that stores "Program Counter" and "Stack Pointer" of interrupted Process written in CPU's interruption instruction registers (like hardcoded). AND special "Sys Stack Pointer" register for OS stack.