Confusion over the use of the "compatible" property in device tree overlays

I’ve read in the wiki’s that the compatible property will hold a list in the format: <manufacturer, model> to indicate board compatibility.

Then there is also where the compatible property will hold a list in the format <manufacturer, model> for hardware on the board so the os will assign the driver best suited for the device - if known by the os.

But the use of the compatible property that seems a little confusing is where the compatible property will hold for example: compatible = “spidev” or compatible = “bone-pincntrl-helper”. My question is are these drivers or functions that are used by the “OCP” to configure or communicate with the peripheral and if they are is there a listing of these driver and or functions that I can access and study?