The usual approach (usual — other than the Filesystem Hierarchy Standard, there is no strong rule to do so, it is just done this way in many distributions) is to have boot-related files stored in
This usually includes
- The kernel image
- An additional image to use as '/' during the early stages of the boot process (optional, and usually used by prebuilt kernels which have a lot of modules, and may require a module to mount the real '/')
- Bootloader files, when the bootloader requires additional files (like GNU GRUB)
That's usually how
/boot is used, I've never seen a system where these files, by default, go somewhere else, but you could always configure your bootloader so that you can use another folder.
These files are required to boot the system, so they're accessed each time you boot. They're actually what you boot when you boot the computer.