Network terminology

Network terminology

Introduction
An understanding of networking is important for anyone managing a server. Not only is it essential for getting your services online and running smoothly, it also gives you the insight to diagnose problems.
This article will provide an overview of some common networking concepts. We will discuss terminology, common protocols, and the responsibilities and characteristics of the different layers of networking.
This guide is operating system agnostic, but should be very helpful when implementing features and services that utilize networking on your server.
Networking Glossary
First, we will define some common terms that you will see throughout this guide, and in other guides and documentation regarding networking.
These terms will be expanded upon in the appropriate sections that follow:
Connection
Packet
Packets
Network Interface
LAN
WAN
Protocol
Some low level protocols are TCP, UDP, IP, and ICMP.
Port
Firewall
NAT
VPN
There are many other terms that you will come across, and this list is not exhaustive. We will explain other terms as we need them. At this point, you should understand some high-level concepts that will enable us to better discuss the topics to come.