Mac Air: Low Disk Space

I ran df-h

And got this:

Filesystem      Size   Used  Avail Capacity  iused    ifree %iused  Mounted on
/dev/disk1     112Gi   73Gi   39Gi    66% 19220714 10101012   66%   /
devfs          183Ki  183Ki    0Bi   100%      632        0  100%   /dev
map -hosts       0Bi    0Bi    0Bi   100%        0        0  100%   /net
map auto_home    0Bi    0Bi    0Bi   100%        0        0  100%   /home

What is map -hosts and map auto_home?