Mode setting

Mode setting e.g. nomodeset

Linux kernels since 2012 have moved the video "mode setting" into the kernel. Programming of the hardware specific clock rates and registers on the video card happen in the kernel rather than in the X driver when the X server starts. This makes it possible to have high resolution, nice looking splash (boot) screens and flicker free transitions from boot splash to login screen. Unfortunately, on some cards this doesnt work properly and you end up with a black screen. Adding the nomodeset parameter instructs the kernel to not load video drivers and use BIOS modes instead until X is loaded.

https://forums.developer.nvidia.com/t/understanding-nvidia-drm-modeset-1-nvidia-linux-driver-modesetting/204068

mode setting (arch linux wiki)

wp:Direct Rendering Manager Note that DRM in this context is Direct Rendering Manager

Basic Input Output System. The part that executes when a computer is first booted and hardware is detected.

Digital Restrictions Management = Electronic methods to control what you can and can't do. In the context of video graphics, it means Direct Rendering Manager.