The different classification of networks are WAN, LAN, CAN, MAN, and PAN.
I will start from the smallest and work backwards, so the PAN is a personal area network, used for near field communication devices, such as RFID, NFC, Bluetooth, etc. It is primarily used for things within the immediate vicinity of the person as the name would imply.

The LAN is probably most commonly used or known. This is your local area network. This is the network used in your home or office to connect all devices on you network.

The CAN is a campus area network, and generally is meant for interconnecting network devices within the campus area.

A MAN is a Metropolitan Area Network, which I had never heard of prior to this class, but is said to be used in the metropolitan area of a city or cities, defined as larger than a Local area network, but smaller than a wide area network.

Finally, we discuss a WAN, or wide area network, which interconnect network devices over a large area, connecting many local area networks to the larger infrastructure. It allows users to communication across networks to share data, print, transfer files etc.