LAN
Local area network, where local is relative. Often described as a building or group of buildings, connected via ethernet or 802.11 wireless.
WAN
Wide Area Networks span the globe, connecting LANs accross a distance.
Can be connected via point-to-point serial, MPLS, etc. and may include both terrestrial and non-terrestrial connectivity.
PAN
Personal area networks may include Bluetooth, IR, NFC, etc. They tend to integrate with our own devices for things such as audio output, etc.
MAN
Metropolitan Area Network
These are networks for cities, larger than a LAN but smaller than a WAN.
Historically there have been specific MAN topologies, although these days we mostly use Metro Ethernet, managed by ISPs.
It is common to see government ownership.
SAN
Storage Area Network.
This is a connection that gives us block-level access to storage devices (unlike a NAS, that gives us file-level access).
Requires a lot of bandwith and are often isolated on their own networks.
WLAN
Wireless LAN 802.11 tech.