To complete the exercise in this chapter, you will need a PC with Windows 11 Pro, at least 8 GB of Random Access Memory (RAM), 500 MB of HDD, and access to the internet.

When you start reading this section, you will naturally wonder why you should learn about computer networking if you are interested in learning about Windows Server. Initially, your statement would stand. However, the more you delve into Windows Server, the more you will justify the necessity of learning about computer networks. As such, this section has been designed to instill fundamental networking skills in you, which are very much needed for installing and supporting Windows Server 2022. So, let’s go back to computer networks.

It all began many years ago when sharing resources became necessary. As time went by and demand increased, the development and advancement of computer network technologies also occurred. Therefore, the need to connect and interconnect computers within computer networks and among more geographic locations created a demand for well-defined terms and concepts to describe computer networks. Because of that, concepts such as computer network types, computer network topologies, computer network architectures, and computer network components were born. As such, a computer network represented one of humanity’s most significant inventions in communication. That said, simply think about the internet, and you will immediately understand how great of a benefit a computer network is to society. More computers were connected to computer networks, and geographical distances were diminished in communication. Therefore, it created a need for well-defined terms and concepts to describe computer networking. Because of that, different types of computer networks, network topologies, architectures, and components have emerged.

Let’s begin by understanding what a computer network is.

What is a computer network?

Merriam-Webster defines a network as “a group of people or organizations that are closely linked and that work with each other.” Furthermore, from the same dictionary, networking is defined as the “exchange of information or services among individuals, groups or institutions.” These definitions will serve as a simple, clear, and concrete way to define computer networks next.

From what was mentioned in the preceding paragraph, a computer network is a group of computers connected through networking devices and networking media to share resources. Usually, when talking about resources, they can be data, network services, and peripheral devices. So, anyone with experience with computer networks has seen that sharing files, applications, printers, and other peripheral devices is simple. Yet, people often confuse what a computer network is with what a computer network does. While the former explains what constitutes a computer network, the latter shows the benefits we get out of it. That is best illustrated in Figure 1.1, where you can see that a computer network is indeed a group of computers connected to share resources:

Figure 1.1 – A typical computer network

A computer network is divided into different types. Let’s take a look at each of them individually.

The types of computer networks

Indeed, the most exciting thing about a computer network is the process of designing and building one. The design and deployment of computer networks are linked to the definition of networking itself. Therefore, the minimal requirement for building a computer network is that there must be two computers. The number of computers on a particular computer network and how they access the resources from the same network determine the categorization of computer network types, which will be explained in the following section.

In general, the categorization of computer networks consists of the area they cover and the purpose they serve. The following subsections describe some of the most popular computer networks used today.

Personal area network

A Personal Area Network (PAN), as shown in Figure 1.2, is a computer network that connects and transmits data between devices in a private area. This so-called private area refers to the space that belongs to an individual. For example, at a working desk at home, you can have your laptop, smartphone, printer, and headphones connected to a PAN via Bluetooth. Bluetooth and Wi-Fi are the most common communication technologies to interconnect devices in a PAN. Often, a PAN is also known as a Home Area Network (HAN):

Figure 1.2 – A PAN

Another type of network is the Local Area Network (LAN). However, its coverage is far greater than a PAN. Let’s learn more about it in the next section.

Local area network

A LAN, as shown in Figure 1.3, is a computer network that connects two or more computers within a local area. Imagine a local area as one single room, a floor, several floors, a building, or several buildings adjacent to each other at a distance that Ethernet communication technology IEEE 802.3 permits. Usually, a LAN utilizes a central device that uses twisted pair, coaxial, or fiber optic cables as a networking media to interconnect computers.

Now that you have learned about PAN, it will be easier to understand what LAN is. Next, let’s compare it with the PAN. A PAN is dominated by portable devices (smartphones), while a LAN mainly consists of fixed appliances. Both computer networks cover the local area. However, the LAN has more extensive coverage than the PAN. For example, a LAN can cover a single floor of the building, several floors of the building, an entire building, or even a few buildings close to one another. Furthermore, while a PAN is primarily organized around a person, a LAN is organized around a site:

Figure 1.3 – A LAN

The next type of network we will look at is the Metropolitan Area Network (MAN). Its coverage is even more significant than a LAN.

Metropolitan area network

In contrast to a LAN, a MAN, as shown in Figure 1.4, represents a group of LANs interconnected within the geographical boundary of a town or city. As was the case with the PAN and the LAN, the MAN’s existence is the need for sharing and accessing the resources inside the city or metro. As a result, a MAN is larger than a LAN in terms of coverage and smaller than a Wide Area Network (WAN). At the same time, the MAN is faster than the LAN and the WAN in data transmission speeds. Nowadays, fiber optics and gigabit Layer 3 switches interconnect LANs and route the traffic, thus enabling MAN’s high speeds:

Figure 1.4 – A MAN

Finally, we will understand a WAN with the most significant coverage.

Wide area network

A WAN covers areas that a LAN or a MAN does not cover. Therefore, unlike a MAN, a WAN, as shown in Figure 1.5, is a computer network covering a wide geographic area using dedicated telecommunication lines such as telephone lines, leased lines, or satellites. As such, WANs do not have geographic restrictions. The internet is the best example of a WAN:

Figure 1.5 – A WAN

Important note

You can learn more about the types of computer networks at https://www.lifewire.com/lans-wans-and-other-area-networks-817376.

Now that we’ve understood the different types of computer networks, let’s look at the underlying components that make up those networks.

Just as PCs have components, computer networks have their components, too. Usually, while PCs and peripheral devices are known to most people, IT professionals mostly understand components such as networking devices, networking media, and NOSes.

First, let’s understand what clients and servers in a computer network are.

Clients and servers

Let’s assume that the network resource is the reference point for clients and servers. Then, in a computer network, clients usually request access to resources. On the other hand, servers are responsible for providing resources and managing access to those resources. Both clients and servers play an active role in the computer network. For example, in Figure 1.6, a server with a directly connected printer provides print services to PCs in the role of print requesters:

Figure 1.6 – The client and server in a computer network

Important note

Interestingly, the origin of the word servers comes from the word serve. If you search for the word serve in the Merriam-Webster dictionary, among the results, you will find one that says "to provide services that benefit or help". Therefore, we can think of a server in a computer network as the computer that provides services to clients. In conclusion, the server serves the clients.

Although clients and servers are the most critical components of a computer network, they take a different naming approach in computer network terminology. So, let’s see how that fits into this structure.

Hosts and nodes

Have you heard about hosts and nodes and wondered what they are? Our first impressions might make us think that hosts and nodes are the same, but they are not! While all hosts can be nodes, not every node can be a host. Hence, a host represents any device with an IP address assigned to its network interface that requests or provides networking services. Usually, clients, servers, and routers act as hosts.

Important note

An Internet Protocol (IP) address is a logical element of decimal numbers separated by a dot. It is assigned to the host’s network interface to identify it in a computer network.

However, a node is any device that can receive and transmit the network traffic but has no interface with an IP address assigned to it. However, nodes have a network interface that is used for their management. For example, in Figure 1.7, the PCs and the file server act as hosts, while switches act as nodes:

Figure 1.7 – Hosts and nodes within a computer network

Now that we have learned what a network is and its components, we can understand its architecture.