Les Hans (chinois simplifié : 汉 ; chinois traditionnel : 漢 ; pinyin : hàn) constituent le peuple chinois « historique », issu de l’ancienne ethnie Huaxia. Celle-ci prend le nom Han à l'époque de la dynastie Han (206 av. J.-C. à 220 ap. J.-C.), et ce nom perdure depuis.
Old age consists of ages nearing or surpassing the average life span of human beings, and thus the end of the human life cycle. Euphemisms and terms for old people include, old people (worldwide usage), seniors (American usage), senior citizens (British and American usage), older adults (in the social sciences), the elderly, and elders (in many cultures including the cultures of aboriginal people).
Old people often have limited regenerative abilities and are more prone to disease, syndromes, and sickness than younger adults. For the biology of ageing, see senescence. The medical study of the aging process is gerontology, and the study of diseases that afflict the elderly is geriatrics. The elderly also face other social issues such as retirement and loneliness.
Because “the precise onset of old age varies culturally and historically,” old age is “a social construct” rather than a definite “biological stage.”