Really dumb statistics question

[Mo0o]

Is there a difference between N and n when im using it to describe a group? Is lower case n suppose to signify a subset of N? Or am I just making this up and theres no difference

 

[FleshLight]

N = population, n = group (subset of population)

That's if IIRC

 

[marketsons1985]

yep, that's true. N is always the entire population where n is the subset.