Water resources include all components of the hydrosphere, such as rivers, lakes, canals, reservoirs, seas, oceans, groundwater, soil moisture, water (ice) in mountain and polar glaciers, and atmospheric water vapor.

Water consumption is typically divided among three main sectors: agriculture, industry, and household. Globally, agriculture accounts for about 70% of total water use, industry 22%, and domestic use around 8%.

In agriculture, water is used not only for irrigating crops but also for recharging groundwater (to prevent rapid declines in the water table), leaching salts from the root zone, controlling pests and diseases through spraying, watering livestock, and processing harvested crops.

Water also plays a critical role in the energy sector.