Virtual water, also called embedded or indirect water, is the volume of water consumed during the entire production process of a product or service, but which is not visible to the end user. It includes all the water used at every step in the value chain to create goods, services, or processes people buy and use daily
. The concept was introduced by John Anthony Allan in 1993 and highlights how water is "hidden" in traded commodities, such as food. For example, importing one tonne of wheat saves roughly 1,300 cubic meters of local water if produced domestically. This trade of virtual water has strategic implications, especially for water-scarce countries, as it allows them to conserve domestic water resources by importing water-intensive products
. Virtual water is important for understanding global water use beyond direct consumption, linking water use to consumption patterns and international trade. It helps analyze water resource management at global, regional, and local levels and informs policies on sustainable water use and food security
. In summary, virtual water is the unseen water embedded in products and services, reflecting the total water footprint involved in their production and trade
