需要 —— 指没有得到某些基本满足的感受状态。
Need is a state of deprivation of some basic
satisfaction.
欲望 —— 指想得到这些基本满足的具体满足物的愿望 。
Wants are desires for specific satisfiers of
needs.
需求 —— 指对有能力购买并且愿意购买的某个具体 产品的欲望。
Demands are wants for special products that
are backed by an ability and willingness to
buy them.