A web-based reference that provides a visual and textual summary of the six main groups. sub-category (like machining or 3D printing) to focus on for your essay? Main groups from DIN 8580 with surface treatment processes

Applying a layer of material onto a solid substrate.

Combining two or more workpieces together.

However, the core content—the of manufacturing—is widely available in open-access academic and technical resources. The "Story" of DIN 8580: The Six Pillars of Manufacturing