MAN (Metropolitan Area Network)
A MAN is a computer network that covers a geographical area that is larger than a LAN but smaller than a WAN,extending typically over a city. It is usually owned by a single entity like a government branch or a large organization.

CAN ( Campus Area Network)
A CAN is a computer network that spans multiple LANs but which is smaller than a MAN. It is mostly present in universities or a campus.

 SAN (Storage Area Network)
This type of computer network is used to connect the servers to the data storage devices for storing the data or accessing the data that was stored previously on the device.

VPN (Virtual Private Network)
A VPN is a network of computers in which some of the links between the various nodes have open connections or have virtual circuits of some larger network, typically the internet, rather than joining them with physical wires. In other words, a VPN uses the connections of the internet or some other intranet to form a private network, without actual physical connection among the devices that form the node. This allows secure communications through the internet, because the VPN can be made accessible only by authorised personnels.

PAN (Personal Area Network)
A personal area network is a network of computers and/or other devices like PDAs (Personal Digital Assistant), cell phones, telephones, fax, printers, scanners etc. This network can be used to transfer files, emails, calender appointments, digital photos, music, etc. A PAN may be constructed through wire or wirelessly, and it typically covers an area of about 10 meters.