Youth, young, youngster, teenager, youthfulness
年轻人 refers to people younger than the speaker, usually people under 30.

少年 refers to people around 13-18.

青年 refers to people around 18-29.

青春 means the time period of or the experience of the age between 12-29. Often it is retrospective, as when you are in mid-age, you might say:回忆青春岁月/悔不该青春虚度, etc. Newspapers may write: 祖国今日之富强有赖于上一辈人挥洒青春. So perhaps it is the reason you get 80s photos