VPN (Virtual Private Network) - definition
A set of communication protocols that allows remote users to securely access a remote network. An example of this technology is when you access your corporate Intranet remotely from your mobile phone.
If your company has a VPN server set up, you can enter the connection details on a supported device and join the corporate Intranet with all user rights and privileges you would have if you were physically there. At the same time, the connection remains secure from unauthorized access.