This package is a kernel driver for the ARM Mali GPU, supporting the 6xx and 7xx series GPUs (first released in 2012 and 2015 respectively). A corresponding binary userspace driver (separately packaged) is also needed to display graphics. In theory separate drivers are needed for midgard (6xx) GPUs and bifrost (7xx) GPUs, however currently the drivers are identical so this driver covers both. This could change in the future. Look up your hardware on https://en.wikipedia.org/wiki/Mali_(GPU)#Implementations if you are not sure what you have. https://wiki.debian.org/MaliGraphics has further details of the Debian packaging, and supported hardware.