Who created the Linux kernel?

Chelseablue 1971, it's a bit of software which provides an abstraction layer for the hardware. Hardware tends to vary between manufacturers and models - it would be impractical for all software to have to address them directly, hence they address the kernel which translates the incoming requests to what is actually required. Windows and OSX have similar architecture.

never heard of this

what's a kernel??

GNU/Linux is good.