What does the prefix 'neo-' denote at the start of a word?

I know the name due to crossword puzzles.

«Νέος» indeed means “young”, or”the young one “ for males… “νεαρές» αre young females «Νέα» is for “news”, thus also for something “new”. This from a Belgian girl that immigrated to Greece, learned Greek from subtitles, and read, speak it fluently! Without bragging… I’m 38 and even write better then most of the “νέο-Γκρέκο” lol I’m so not joking 👀