What is Intranet? - Explained

There are open networks that can be accessed out of the network and there are networks that cannot be accessed outside the network.

What is Intranet? 

Intranet is a type of network that cannot access outside the network. Maybe there's no connectivity or maybe just the firewall which blocks the requests that need to go outside the network.

Intranets are commonly possible to see in the government offices and other places where the security and other aspects are tight. North Korea does have an Intranet inside the country and hardly few got the opportunity to get connected to the internet. 

Intranet can be set up in a local area network and a larger WAN also could have the characteristics of an Intranet.