What's the difference between retort and aseptic packaging?

In retort packaging, food is filled into a pouch or metal can, sealed, and then heated to extremely high temperatures, rendering the product commercially sterile. In aseptic packaging, the food or beverage is sterilized by quick exposure to ultra-high heat, rapidly cooled to an ambient temperature, and filled into sterilized containers that are then sealed in a commercially sterile environment. However, the assembled aseptic package is not further processed like retort products.