What is the real difference between LAN and WAN?

Solution 1:

Many Answers here have given textbook-like definitions that have touched on this, but there are certain practical, real-world distinctions worth underscoring:

A LAN is typically something completely within your own premises (your organization's campus, or building, or office suite, or your home), so it's something you build and own yourself, all the way down to the physical cabling. In contrast, a WAN is something that connects between geographically separated locations, so you generally have to lease access to lines or data transmission services from telecommunications carriers to create your WAN.

Because of the shorter distances needed for on-premises networks, and because of the focus on connecting PCs and servers, LANs tend to be built on Ethernet and other 802.3-family (and 802.11-family) physical layers and data links. 1000BASE-T, 1000BASE-SX, 1000BASE-LX, etc.

Because off-premises network links usually need to go longer distances and work over the telecommunication carriers' existing infrastructure, they tend to use physical and data-link standards that are more common in the telecom industry. Then again, for your convenience, telecom carriers usually hand off to you using an 802.3-family link, even if what they're using behind the scenes is, say, OC-3 and SONET/SDH.

Because of the technical hurdles associated with moving lots of data long distances reliably, WAN links tend to be lower bandwidth and higher latency than LAN links. Also, because you're usually paying a separate telecom carrier for the service, to keep costs down, most organizations try to limit (or at least not go crazy with) how much data they move over WAN links.

The differences between LANs and WANs tend to be at the physical and data-link layers. At the network layer (Layer 3 in the old-but-still-helpful-for-some-discussions OSI layering model), most people use IP (Internet Protocol) nowadays. Because it all uses IP, applications that use IP don't have to know what physical and data-link layers are in use, so anything you can do on a LAN you can potentially do on a WAN as well, if you have high enough bandwidth and low enough latency for whatever it is you're trying to do, and as long as you haven't blocked it at your firewall (or via the accidentally firewall-like properties of a NAT).

Solution 2:

While LAN and WAN are both two branches of networking and share many similarities, there’s a very fine line between them as well

There are differences on the basis of scope and connections. When I was doing my Cisco qualifications I seem to recall that a WAN was typically over a large geographical area, like a huge private network (mini internet [intranet])

http://www.computer-realm.net/lan-wan/

• Difference on the basis of scope: WAN is considered to be more vast and widespread. WAN is meant for networking between wide geographical regions like between two cities or even across different time zones while LAN is mainly used for private connectivity among residential offices or a single edifice. Hence a small scale WAN can be developed by creating many LANs.

• Difference on the basis of connections: In case of LAN, Ethernet is the main device which is used for connecting the workstations or the computers. Ethernet is a bus based protocol device in which cables and wires and permanent. Ethernet helps is the interconnection of the different types of LANs. While in the case of WAN, common carriers are usually used and most people opt in for service providers. When it comes to the speed of both the network technologies, a LAN is usually faster as it is confined to a small space with servers in a nearby location.

Solution 3:

Networks are often classified by their physical or organizational extent or their purpose. Usage, trust level, and access rights differ between these types of networks.

Computer network types by area:

Body (BAN)
Personal (PAN)
Near-me (NAN)
Local (LAN)
    Home (HAN)
    Storage (SAN)
Campus (CAN)
Backbone
Metropolitan (MAN)
Wide (WAN)
Global (GAN)
Internet
Interplanetary Internet

LAN: A local area network (LAN) is a computer network that connects computers and devices in a limited geographical area such as home, school, computer laboratory or office building.

WAN: A wide area network (WAN) is a telecommunication network that covers a broad area (i.e., any network that links across metropolitan, regional, or national boundaries).