WAN = Public Network : The Internet is a public network

LAN = Private Network : A private network is a network which only authorized user can access and given permission

EXAMPLES:

WAN - the internet is a WAN. Because you are reading this post on the internet, you are accessing this page through a WAN Network

LAN: if you have DSL or CABLE at home, and if you have a switch or router

How can you tell if you are in a WAN or LAN Network. its very hard to tell unless you are the network engineer or network technicians.

an WAN is basically a large network, for example, a corporation that has two offices in the united states, one in New York and the other in Los Angeles

the New York office may have a LAN to connect its employees within the NY office. BUT uses a WAN to connect to the Los Angelese Office.

same with the Los Angeles office, they have a LAN for their office in LA, and if an employee from LA wants to share a file with another employee in NY, they will have to use their WAN network, but if the LA employee is sharing a file with another employee in the LA office, then they are most likely using their LAN to share the files

ADVANCED: NAT (Network Address Translation) uses LAN to connect users in within a local network. most commonly when you are in a NAT network, your IP Address could begin like this:

private address
10.x.x.x (Class A Address)
172.16.x.x (Class B Address)
192.168.x.x (Class C Address)