Hi Apugers!

Until recently I did B&W on film and colour digital, but I discovered I hardly touched my digital camera for months since I fell in love with film.
I know very little about colour film but want to learn to know it so I would like to know a few basic things.

Is the only difference between slides and negatives that slides are used for projection and negatives mainly for prints? Or can slides be used for prints just as good? (And are there other reasons why people choose the one or the other.)

My main interest on colours in skin tone, I have tried some films and scanned them. Fuji Astia seems a lot better than Velvia for this purpose, Kodak ektachrome is ok as well. Is it worth to try negative film as well, eventually the pictures have to be on print...