Nanoscale technology is a branch of nanotechnology in which standard size tools are used to manufacture simple structures and devices with dimensions on the order of a few nanometer s or less, where one nanometer (1 nm) is equal to a billionth of a meter (10 ^-9m). Nanoscale technology encompasses all of nanotechnology except molecular manufacturing, which involves the use of nanoscale (extremely small) tools to build structures, devices, and systems at the molecular level. Nanotechnology has potential benefits in a number of fields, including water purification, sanitation, agriculture, alternative energy (particularly photovoltaics), home and business construction, computer manufacturing, communications, and medicine. Nanotechnology is also considered to pose risks, including economic disruption, misuse by people or organizations with nefarious intent, evolution of extreme governmental regulation, controversies over morality, and damage to the environment