Article explains characteristics of VPN and definition of Virtual Private Network configuration.
From a user perspective, each user is on the internal network. Each has access to all the resources available to someone who is physically connected to the local LAN. The speed or bandwidth is probably the only noticeable difference in a true VPN configuration.
From a connectivity standpoint that is, buts going over the wire, however, there is a significant difference regarding virtual private networking. The VPN must package up all the bits, encrypt them to keep the private in VPN, and then send them over the public network to the destination.
All VPNs have definite utilities and structures that create them VPNs. These utilities deal with encryption, authentication, tunneling, and prevention of internal network access via any other means that the VPN itself.
The P in VPN stands for private. This means that in some manner the data in the communications is not generally available for others to see. In the context of public networks and the Internet as a specific example, this means that the data must be encrypted. That is correct, except now you need to ensure that you are encrypting with the person you choose. This is where authentication cones in.
You have to have a way to get packets that should only be on the internal network transported over the other side of the VPN link. This is where tunneling comes in. We take a packet that has only internal information in it and package it up for transport over the public network. The VPN then uses a tunnel as the transport mechanism of this packet.
You need to protect your internal network, so by definition, a virtual private network VPN has some firewall capability. It will not permit any outside transportation into the internal network except it goes through the VPN and thus acts as a firewall.
Recognizing that clear-text traffic sent across a public network results in major security-related risk does not by any means require extensive security-related experience. But does any real-world evidence exist to corroborate the security-related threats concerning the unauthorized capture of clear-text network traffic are real? The answer is definitely yes. The perpetrators gleaned clear-text passwords and the broke into one account after another. At one point, one investigator reported that some perpetrators have captured so many passwords that they had to stockpile them, saving them for use much better.