These puzzling letters are abbreviations for some protocol terms. These protocols are used to encrypt confidential materials in networking. A while ago, lines connecting two points were conducted to transfer data without danger. In those days the total expenses were quite heavy. VPN gives its customers a secure way to access corporate, public or private networks with no need for those lines. VPN is a set of technologies/services which are used here for customers’ protection and safe traffic transmission through the Internet. It’s perfectly clear to everyone, that IP doesn’t provide safeness functions. PPTP, L2TP, IPSec, SSL protocols are used to organize a VPN tunnel, which in its turn adds security to data transference.