VPN stands for virtual private network. The virtual means that this privacy is accomplished allthough it is by nature not private at all when you communicate over a public network - the internet. The data flows through all kinds of networks. All of them being owned and operated by someone else than you or your company, so from a privacy point of view: Those networks can not be trusted. So the virtual privacy is being achieved by strong encryption. This creates the methaphor that is a private network because only allowed people are connected or configured to enter the encrypted space.
There are lots of software packages and some different protocols that are used to operate VPNs.
The count of software packages are plenty. The protocols are relatively few, like:
- IPSec
- OpenVPN
- wiregard
- Closed source vendor specific implementations, created completely on their own or based on one of the above
The different properties of a vpn solution are:
- Manageability(Tools to manage Access and Accounts and Distribution)
- Compatibility with protocols(as shown above)
- Closed Source/Open Source
- Commercial products usally introduce their own hardware product series to be used with the VPN software