一代 is often used in elevated or literary expressions: 一代宗师 (grandmaster of a generation), 一代枭雄 (hero/strongman of an era), 一代人 (a generation of people).
usage
下一代 (xià yīdài) = the next generation. 新一代 (xīn yīdài) = the new generation. 代沟 (dàigōu) = generation gap.
