Well, I'm not actually sure which one they're referring to but there is two meanings that I know of. There's the Software Developer Kernel which is the core of

Well, I'm not actually sure which one they're referring to but there is two meanings that I know of. There's the Software Developer Kernel which is the core of an operating system, and there's the Linear Algebra Kernel which is the null space of a map. Most of us here are familiar with the operating system type but the linear algebra kernel describes the set of vectors which are sent to the null vector (0) by your transformation/map/operation. It's very useful in understanding what exactly your operator does and how it changes a space.