VPN is short for Virtual Private Network and is just a technology that produces an encrypted secure connection over a less secure network such as the Internet. The advantage is so it offers the security that the network where it is situated cannot provide. It uses the internet to move data. Many such networks could be developed by using different systems incorporating encryption and other security mechanisms to make sure that only authorized users can access the network and information cannot be intercepted by the others. It is similar to a tunnel created to transmit data between a network of say an organization and a remote user. It hides important computer data and IP address.
The key VPN network protocols are:
IPSec - Produced by the Internet Engineering Task Force, to secure exchanges of data at the IP layer. It is widely employed for creating VPNs
PPTP- Indicate Point Tunneling Protocol for VPNs developed jointly by Microsoft, US Robotics and several remote access vendor companies. It's now obsolete because of security concerns
L2TP - Layer 2 Tunneling Protocol is an extension of the PPP Protocol (PPP, which establishes connectivity between 2 nodes or computers) L2TP allows ISPs to use VPNs
SzL - Secure Sockets Layer may be the commonly used one nowadays which can be combined with a standard web browser. Unlike IPSec, it generally does not require installing specialized client software on the finish user's computer.
VPN decreases your internet. The factors affecting the speed will be the number of people using the VPN and the geographical location.
It is used on a person level - Consumers make use of a private VPN service or tunnel to protect their identity and online activity. This really is especially relevant whenever we use public wifi which might not be secure. You need to use anonymous VPNs, which serves as a privacy buffer between you and your Internet Service Provider, who otherwise has usage of your internet usage patterns. VPNs are employed extensively by BitTorrent users.
Corporates utilize it to communicate in confidentiality video, voice or data over a public network. It can also be a wise decision when employees are scattered all around the globe. VPNs help connects global offices. Corporates either use a VPDN which helps hook up to an organization LAN through dial up or site-to-site- VPN where dedicated hardware can also be used for connecting multiple sites to the business LAN.