Evaporated milk, also known as dehydrated milk, is a long life, shelf stable canned milk product with about 60% of the water removed from fresh milk. It differs from condensed milk, which contains sugar. Condensed milk requires less processing because the added sugar inhibits bacterial growth.
Because it could be reconstituted by adding water, evaporated milk was popular before refrigeration as a substitute for perishable fresh milk. In present times, household use is most often for desserts and baking. When mixed with an equal amount of water, it can be substituted for fresh milk in recipes.
Evaporated milk has a shelf life of months (and sometimes years), depending on the brand.