means The collection of tools, software, and equipment used to build, test, or manufacture something — or the act of working a surface with such tools.

from From Old English 'tōl,' an implement or instrument, itself from a Germanic root meaning roughly 'to make or prepare.' The '-ing' turns the noun into an activity or collective, and by the industrial age 'tooling' named both the specialized equipment fitted to machines and the work of shaping leather, metal, or stone with it. Software borrowed the word later, treating code the way a machinist treats a lathe.