Quartz Compositor

The Quartz Compositor is the display server and compositing window manager for MacOS. Quartz can be considered as the MacOS equivalent to something like labwc, sway or niri. Quartz also is GPU-accelerated and has full support for transparency.

Quartz reads data out of a specific memory location or a backing store and then assembles them onto the display. The backing stores are used to always keep track of the data that should be displayed, so when two windows on top of each other get moved away, the window manager doesn’t need to figure out what it should draw, but rather already knows it. Quartz then continues to draw the resulting image into the frame buffer of the GPU.

There is also an event queue that Quartz manages. It takes events such as key strokes and mouse clicks and passes them to the correct application.

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