In your average, memory-protected environment, a "context" is a virtual address space, the executable contained in it, its data etc.| wiki.osdev.org
Interrupts are signals from a device, such as a keyboard or a hard drive, to the CPU, telling it to immediately stop whatever it is currently doing and do something else. For example, a keyboard controller can send an interrupt when a character key was pressed. Then the OS can display the character on screen immediately, even if the CPU was doing something completely unrelated before, and return to what it was doing afterwards. When a specific interrupt arises, the CPU looks up an entry for t...| wiki.osdev.org
The factual accuracy of this article or section is disputed.| wiki.osdev.org