一代 (yī dài) refers to a generation as a distinct group or period, often used with a modifier like 这一代 (this generation) or 新一代 (new generation). It differs from 世代 (shì dài), which emphasizes a lineage of generations (e.g., 世代相传 'passed down for generations'), and from 后代 (hòu dài) 'descendants' or 后世 (hòu shì) 'later generations/posterity'.