The Computation Pipeline - Practical Rendering and Computation with Direct3D 11 - page 290

Figure 5.1 . A visualization of the threads within a thread group.
the thread group. Similarly, we can visualize all of the thread groups defined by the dis-
patch call as a three dimensional array, as shown in Figure 5.2.
If we combine the two previous images, we can get a sense for how each individual
thread is located within the complete system of threads instantiated by the dispatch call.
This is shown in Figure 5.3.
Figure 5.2. A visualization of the thread groups within a dispatch call.