Seed will live along time if kept cool and dry but will eventually die. Germination refers to the process by which the stored food imbibes water, swells, splits the seed coat, and the embryo begins to grow. Germination cannot occur until proper conditions for germination have been met and dormancy mechanisms have been overcome. Proper environmental conditions for germination vary with seed. All seed need moist soil to germinate but too much moisture can favor disease organisms that will destroy the seed or seedlings.
Many seed have some type of dormancy mechanism.
This is a protective device whose purpose is to keep the seed from germinating at the wrong time. For example, for many plants in the Delhi area, environmental conditions may be right for seed germination when the seed fall from the parent plant in the fall, but if the seed germinated then it would have little chance to become an established plant before winter set in. Thus most plants native to this area have some type of dormancy mechanism to prevent fall germination. Plants from warm climates with no strong seasonality usually have no dormancy mechanisms. Most commonly grown vegetables and annual bedding plants have no dormancy mechanisms.