What is vpn and how does it work?

Answer 1

VPN stands for Virtual Private Network. It is an illusion of a Wide Area Network, but in reality it is a group of Local Area Networks connected to the internet.

The reason for this will be explained by this example

If you start out a very successful IT-business in London and want to expand to New York, you will have two LANs: one in each city. If you want to create a WAN, then the old way would be like this: "Let's pull a cable across the ocean.". The big issue would be the price tag. That's why VPN is invented.

You have the same situation, but now we are going to use the Internet as a connector between the LANs. To secure the communication between those LANs to create a VPN, you have to use the tunneling principle: you create a 'tunnel' between the two LANs by wrapping each package you send into an extra shell before the actual sending over the Internet. If the case of package loss happens, then the 'finder' would not have the opportunity to read the data in that package because of that extra shell.

Well, in a nutshell:

A VPN is a group of two LANs connected to the internet and communicating between each other by using a 'tunnel', which is an extra shell wrapped around the data before the actual sending over the internet.