VPN allows individuals sends and/or receives data across public network as if they are connected to a dedicated private network. For example, people in their own home can access to their corporate private sites using VPN provided by the company. This negates the need for Point-to-Point/Leased Line. To avoid eavesdropping, a typical implementation of VPN involves authentication and encryption using #IP Security (IPsec).
VPN encrypts# the traffic in Network Layer.
Network Security is a measure whether the data is protected during transmission. This could be strengthen by preventing physical and unauthorised remote access to network devices, specialised firewall systems, Access Control Lists (ACL), Intrusion Prevention Systems (IPS), and Virtual Private Network (VPN)#. For home user, it can be done using antivirus, antispyware, and firewall filtering.
MPLS is a Data Link Layer# #Wide Area Network (WAN) backbone technology that delivers WAN and MAN services. It is one of the alternative to replace the legacy Frame Relay, Asynchronous Transfer Mode (ATM) and Point-to-Point/Leased Line as it can provide their functionalities in a multiservice form. Though it can be used to aggregate and transport Frame Relay, ATM, and IP-based traffic, the former two could be done using Any Transport over MPLS (AToM) technology. It also provides the Virtual Private Network (VPN)# technology.
ISP forms the backbone of the Internet as they provide services for accessing, using and participating it. Though they have a great power on controlling what content should their users access, it is easily by-passable by changing Domain Name Server (DNS) or using Virtual Private Network (VPN)#.