It came on different disk sets; you really only needed the 'a' (base) set, but the 'n'etworking set was useful if you wanted the thing to connect to anything else.
IIRC there were also
d: development (gcc, make, etc)
e: emacs (I think; I used vim at the time)
x: X11 base system
xap: X applications
y: bsd games