Description
An age change is a process of change occurring progressively with the chronological passage of time in all members of a species. Human skin, for example, thins and becomes more transparent and less elastic with age. An age difference, however, is simply a difference observed when directly comparing individuals of different ages: a difference which may not be purely due to the ageing process. The use of walking aids, more common in the elderly than the young, is an age difference not purely due to the ageing process.
