[Haskell-beginners] Need help groking the statement: expression1 in term:expression2

[Olumide]

Hello List,

I'd appreciate help understanding the second line of following block of 
code (from LYH, first line added for completeness),

http://learnyouahaskell.com/input-and-output#randomness
randoms' :: (RandomGen g, Random a) => g -> [a]
randoms' gen = let (value, newGen) = random gen in value:randoms' newGen

The part I'm really struggling with is random gen in value:randoms' newGen

Thanks,

- Olumide