A qanat or kārīz is a system for transporting water from an aquifer or water well to the surface, through an underground aqueduct; the system originated approximately 3,000 years ago in what is now Iran. The function is essentially the same across North Africa and the Middle East but the system operates under a variety of regional names: qanat or kārīz in Iran, foggara in Algeria, khettara in Morocco, falaj in Oman and the United Arab Emirates, karez in Afghanistan and Pakistan, uyūn in Saudi Arabia, etc. The largest extant and functional qanat systems are located in Iran, Afghanistan, Oman, the oases of Turfan region of China, Algeria, and Pakistan.

A well is an excavation or structure created in the earth by digging, driving, or drilling to access liquid resources, usually water. The oldest and most common kind of well is a water well, to access groundwater in underground aquifers. The well water is drawn up by a pump, or using containers, such as buckets or large water bags that are raised mechanically or by hand. Water can also be injected back into the aquifer through the well. Wells were first constructed at least eight thousand years ago and historically vary in construction from a simple scoop in the sediment of a dry watercourse to the qanats of Iran, and the stepwells and sakiehs of India. Placing a lining in the well shaft helps create stability, and linings of wood or wickerwork date back at least as far as the Iron Age.