What does the kernel do?

Linux began in 1991 when Linus Torvalds started writing an operating system for Intel 386- and 486-based personal computers. He was inspired by the Minix operating system written by Andrew S. Tanenbaum 4 years earlier. Linux differed in many ways from Minix; the main difference being that it was a 32-bit virtual memory kernel and the code was open source, later released under the GPL v2 license. He announced it on August 25, 1991, on the comp.os.minix newsgroup in a famous post that began with the following:

Hello everybody out there using minix—I'm doing a (free) operating system (just a hobby, won't be big and professional like GNU) for 386(486) AT clones. This has been brewing since April, and is starting to get ready. I'd like any feedback on things people like/dislike in minix, as my OS resembles it somewhat (same physical layout of the filesystem (due to practical reasons) among other things).

To be strictly accurate, Linus...