What is the difference between a basic field strip cleaning and a detailed gunsmith cleaning?

A basic field strip is disassembling the firearm to its major components, cleaning those components, lubricating it to factory specifications, and reassembling the components with a safety check.  A detailed gunsmith cleaning involves the complete disassembly of the firearm, removing every small component, inspecting the components to ensure reliable and safe function, removing all carbon from the firearm, reassembling the components, lubricating the firearm, and safety testing.