Step 1: Compare the two on 'why' the animals are kept.
A nomadic herder keeps animals mainly to feed and clothe the family, so the herd's output rarely leaves the community. A commercial rancher keeps animals as a business, so the output is sold in distant markets, often exported.
Step 2: Compare on 'how' the animals are managed.
The nomadic herder moves constantly, following natural pasture and rainfall, using simple traditional knowledge. The commercial rancher stays on one large enclosed ranch, using fencing, selective breeding and modern veterinary science to raise output per animal.
Step 3: Compare on scale and technology.
Nomadic herds tend to be smaller and use almost no machinery, while commercial ranches often run thousands of animals with heavy use of machinery, refrigeration and transport infrastructure to reach world markets.
Final Answer:
The two systems differ in purpose (subsistence versus commerce), movement (migratory versus fixed ranch) and technology (traditional versus scientific and mechanised).$\boxed{\text{Different in purpose, movement and technology}}$