It all started as a need to share resources! Starting with the initial design of computers in the 1950s, the impetus to use computers to communicate was first realized in the 1960s as a number of university computers on different campuses were interconnected. Over time, the development and advancement of computer network technologies took place. Thus, the need to connect and interconnect more computers to computer networks and with it more geographical locations created a need for well-defined terms and concepts to describe computer networking. Because of this, types of computer networks, computer network topologies, computer network architectures, and computer network components were born. Certainly, computer networking represents one of the biggest inventions of mankind in the field of communications. Simply mention the internet and one will immediately understand how huge the benefit of computer networks is to humanity.

Before offering the definition of a computer network, let us first look at the general definition of a network in order to then recognize the computer network definition. If you search for the word network in the Merriam-Webster dictionary, you will find the following definition: "network is a group of people or organizations that are closely linked and that work with each other." In the same Merriam-Webster dictionary, the phrase networking means "exchange of information or services among individuals, groups or institutions." Based on that, the computer network is a group of computers connected to each other in order to share resources. When talking about resources in a computer network, usually the resources can be data, network services, and peripheral devices.

Obviously, when talking about computer networks it is essential to mention components of a computer network because computer networks are ultimately composed of their constituent components. Usually, computers and peripheral devices are just some of the computer network components known to most people. However, there are also intermediary devices and network media.

When talking about hosts and nodes, although their first impression might drive us towards thinking that they are the same thing, in fact they are not! The difference between hosts and nodes is that, while all hosts can be nodes, not every node can act as a host. Because every host is assigned an Internet Protocol (IP) address (see the IP addressing and subnets section for more on IP addresses). There are some nodes such as hubs, bridges, switches, modems, and access points that have no IP address assigned, but are still used for communications. So, a host is any device that offers networking resources to any other node and user on the network. In contrast, a node is any device that can generate, receive, and transmit the networking resources on the computer network. Based on that, Figure 1.1 represents a computer network with hosts (servers, printer, PC, laptop) and nodes (switch).

Since computer networks have been designed to share resources then it is very important to look at the way these resources are shared. Let us try to understand precisely, the computer network components that share resources and computer network components that request resources. For example, when accessing social networking portals on the internet, we know that our device is the network component that requests resources, while the devices where social networking applications are located are network components that provide resources. However, there are situations when these computer network components exchange roles, from requesting a resource to providing a resource and vice-versa, and that is going to be explained in the next section, Understanding network architectures.

Now, going back to the concepts of requesting a resource and providing a resource, actually, that is what is shaping the definition of clients and servers in the computer network. Clients, in most cases, are computers that request the resources in a computer network. Because they are components, the clients have an active role in the computer network. Furthermore, servers are a network component that provides resources to clients. Servers too have an active role. The following figure, Figure 1.2, presents the server with a shared printer in the role of resource provider, and the PC, laptop in the role of resource requesters.

When talking about computer networks, actually we are talking about the essential and broader concept of the elements that make up a computer network. In this form of discussion, while the computer network types deal with the area coverage, the physical and logical topologies deal with the physical arrangement and logical structure of the computer network. Having said that, the computer network architecture represents the computer network design that allows the computer network components to communicate with one another. Usually, there are two types of architectures in a computer network:

• Peer-to-peer networking (P2P): This is a computer network in which the participating computers do not play the predefined roles in the network, instead they change roles from client to server and vice-versa based on the actual activity on the network. For example, if computer A is accessing resources from computer B, then computer A acts as the client while computer B acts as the server. After some time, if computer B accesses resources from computer A, then computer B becomes a client and computer A becomes a server. As you may notice, they switch roles based on who is requesting and who is providing a resource on the network. Figure 1.1 presents an example of peer-to-peer networking:

• Client/server networking: This is a computer network in which participating computers have a predefined role. That means that in this computer network architecture, computers that access resources act as clients, while computers that provide resources act as servers. In general, this is a computer network architecture with dedicated servers that provide resources on the network. Mid-sized and enterprise computer networks are the best example of the client/server computer network. Figure 1.2 presents an example of client/server networking:

Nowadays, a lot of effort is being made to advance the development of IP addressing technologies. Specifically, IPv6 addressing is the best example of such an effort. Nevertheless, even though the IPv6 addressing technology is becoming more and more plausible, it still prefers the role of spectator in the great arena of the internet, where IPv4 addressing technology continues to be the norm.

• IPv4 addressing technology is the fourth version of IP addressing. In brief, an IPv4 address, or simply IP address, is a logical element that consists of 32 bits. It is organized into four (4) groups of eight (8) bits (octet) each divided by a decimal point. For the purpose of easier interpretation, it is represented in decimal format (for example, 192.168.1.1). Knowing that one (1) byte equals eight (8) bits, then an IP address is four (4) bytes. From that, the total number of IPv4 addresses is 2³² , or 4,294,967,296. When compared with the total world population, it is obvious that nearly 3 billion IP addresses are missing if we assign an IPv4 address to every individual.
• IPv6 addressing technology has been introduced to overcome IPv4 limitations. Similar to IPv4, IPv6 is a logical component of computer networks too. However, it consist of 128 bits organized into eight (8) groups of sixteen (16) bits (hextet) each divided by a colon. For the purpose of easier interpretation, it is represented in hexadecimal format (for example, 2001:0DB8:85A3:0000:0000:8A2E:0370:7334). From that, the total number of IPv6 addresses is 2¹²⁸ , or 340,282,366,920,938,463,463,374,607,431,768,211,456. And that is more than enough IPv6 addresses!
• IPv4 subnetting helps implement multiple logical networks within existing IPv4 classes such as A, B, and C. In subnetting, a subnet mask plays an important role in determining the size of the network. So, by definition, a subnet mask is a 32-bit address used in combination with an IPv4 address to indicate the network and its computers. Each class has a default subnet mask. Table 1.1. shows the default subnet masks for each class of IPv4 addresses.

Table 1.1. Default subnet masks for each class of IPv4 addresses:

In an attempt to combine the performance of Windows Server 2008 with the robustness and advanced security of Windows Server 2012, Microsoft created Windows Server 2016. Equipped with the best technologies of both worlds and the newest inventions in the Windows Server environment, Windows Server 2016 became the first server operating system designed specially for the cloud. That said, Windows Server 2016 is shaping the new era of computing, that of cloud computing.

A Network Operating System (NOS) is software that is capable of managing, maintaining, and providing resources in the network. Additionally, NOS is capable of sharing files and applications, providing web services, managing access to resources, administering users and computers, providing tools for configuration, the maintenance and provision of resources, as well as other functions related to network resources. With that in mind, a NOS is an important component when it comes to managing computer network resources. Nowadays, the operating systems offered on the market, such as Windows, Linux, and macOS, are known as NOS because they are capable of providing resources. Of course, if you want to take advantage of their resource provider potential then you should go with server versions of the aforementioned operating systems.

Figure 1.3 shows the most commonly used NOS today:

In general, computer hardware is any physical component regardless of the material that it is made of, such as metal, plastic, or wood. On the other hand, software is the instruction or program that tells hardware what to do. It is a virtual component which we have no physical contact with and is represented by the OS, programs, utilities, and any other type of software. When talking about the server's hardware and software, the computer definition of hardware and software applies to servers as well. However, as already explained, because servers provide network services, more powerful hardware is required. At the same time, the software is different too. For example, Windows Server 2016 is different to Windows 10 although both are Microsoft's products.

Now that we have explained the concepts of hardware and software, the following points outline the hardware components that affect the overall performance of your servers, thus you should not make any compromises when you want to build or buy, and set up a server.

• Processor: A chip on a server's motherboard, often called the computer's brain, that does all the processing and calculations. Intel and AMD are the well-known processor manufacturers. The newest processors on the market are 64-bit architecture compared to the old ones of 32-bit.
• RAM: Stands for Random Access Memory (RAM). It is a working memory used by your server's OS and applications. The more RAM you have in your servers, the more applications you can run simultaneously.
• Disk: This is where you store data on your servers. Usually servers have more than one disk known as a server's disk sub-system. The higher the read-and-write speed, the higher the performance of your disk system.
• Network interface: Provides a network connection in and out of your servers. Usually servers have more than one network interface. The higher the speed of your server's network connection, the faster the server can send and receive data over the network.

Concerning the size and form factors, servers come in three formats:

1. Rack mountable servers: These are traditional big servers that are mounted on a rack
2. Blade servers: These are usually small modules known as blades that are mounted on a server's chassis to save space.
3. Tower servers: These are single servers that stand upright.

What is your answer if someone asks you, What is Windows Server? I am sure you will answer that it is Microsoft's NOS for servers. In general, when talking about servers, whether it is a server that runs on Windows, Linux, or macOS it still does not make any difference as it continues to be a server that provides network services. But, when talking about how to deploy a server, the user interface, managing resources, and maintaining a server, then the differences are obvious.

After nearly two years of public testing through its Technical Previews one to five, Microsoft released Windows Server 2016 as the latest NOS for servers. The improvements made in server roles and features, virtualization, storage management, and security have made Windows Server 2016 more stable, robust, scalable, and secure. Additionally, the introduction of Nano Server as a new installation option, together with Windows Server containers, nested virtualization, shielded virtual machines, Storage Spaces Direct, and many other improved and new features, represents the tremendous potential that Windows Server 2016 adds to an organization's network infrastructure. Another interesting thing in Windows Server 2016 is the return of the Start Menu.

Planning before you start deploying Windows Server 2016 will save you time, reduce costs, and provide a platform for you or your business to set up and run the services on your network infrastructure. To do so, you need to know the available editions of Windows Server 2016. Windows Server 2016 comes in three editions:

• Windows Server 2016 Datacenter: This edition is designed for enterprises that own highly-virtualized data centers or act as cloud providers.
• Windows Server 2016 Standard: This edition is designed for medium-sized businesses that use servers on-premises to run their network services.
• Windows Server 2016 Essentials: This edition is designed for small businesses that run a single server in their IT infrastructure.

As with the installation of previous versions of Windows Server, pay attention to the minimum hardware requirements. Windows Server 2016 has the same minimum hardware requirements as Windows Server 2012. Thus, it is required that you have the following or better hardware to install Windows Server 2016:

• Processor: 1.4 GHz with 64-bit architecture
• RAM: 512 MB
• HDD: 32 GB
• Monitor: It must support Super VGA (1024 x 768) resolution and above
• Other hardware: Has support for optical disk drives such as DVDs and support for SSDs with USB, keyboard, and mouse
• Internet connection: cable or DSL connection

However, if you want to avoid slow performance of your server then there are also recommended system requirements:

• Processor: 2.0 GHz or higher
• RAM: 32 GB or higher
• HDD: 1 TB
• Monitor: It must support Super VGA (1024 x 768) resolution and above
• Other hardware: Has support for optical disk drives such as DVDs, support for SSDs with USB, keyboard, and mouse
• Internet connection: cable or DSL connection
• Network access: at least one Gigabit Ethernet NIC

As you might know, Windows Server 2016 is not free! So, whether you are using it for your own personal experience or to provide network services for your company, Windows Server 2016 is a NOS that you need to pay for. However, Microsoft, through the TechNet Evaluation Center (https://www.microsoft.com/en-us/evalcenter) web portal provides the option to download and explore all the new improvements of Windows Server 2016 as evaluation software as shown in Figure 1.4.

In case your server's hardware is the same as, or exceeds the minimum hardware requirements as described above, then you can download a Windows Server 2016 evaluation version. To do so, try completing the following steps:

1. Open up your browser and navigate to the following website: www.microsoft.com/en-us/evalcenter/evaluate-windows-servers-2016.
2. Click the Sign in button. On the next page, provide your Microsoft account credentials. If you do not have a Microsoft account then you can sign up for one.
3. Select the preferable file type (my recommendation is ISO), and then click Register to continue.
4. A form should be filled in for the download to begin. On the same form, if you would like to hear from Microsoft or Microsoft partners, then check the My email address checkbox.
5. Click the Continue button. Then, select the language for your Windows Server download. Shortly, the Windows Server 2016 download will begin. If not, you can go on and click the Download button.

6. Once your Windows Server 2016 download completes, then you should burn the ISO file to a DVD. If you do not know how, then follow the instructions from the following URL: https://support.microsoft.com/en-us/help/15088/windows-create-installation-media. When done, you are all set to move on with the installation of the Windows Server 2016 evaluation version:

1. Get started with Windows Server 2016 (https://docs.microsoft.com/en-us/windows-server/get-started/server-basics)
2. What's new in Windows Server 2016 (https://docs.microsoft.com/en-us/windows-server/get-started/whats-new-in-windows-server-2016)
3. Important issues in Windows Server 2016 (https://docs.microsoft.com/en-us/windows-server/get-started/windows-server-2016-ga-release-notes)

We summarize the chapter with following points:

• A computer network is a group of computers connected to each other in order to share resources.
• The components of a computer network are the substance that constitutes the computer network.
• A host is any device that offers networking resources to any other nodes and users on the network.
• A node is any device that can generate, receive, and transmit the networking resources on the computer network.
• A client is a computer that requests the resources in a computer network.
• A server is a network component that provides resources to the clients.
• Peer-to-peer (P2P) networking is a computer network in which the participating computers do not have predefined roles in the network.
• Client/server networking is a computer network in which participating computers have predefined roles in the network.
• NOS is software that provides, manages, and maintains resources on the network.
• Computer hardware is any physical component regardless of the material that it is made of, such as metal, plastic, or wood.
• The software is an instruction or the program that tells the hardware what to do.
• A processor is a chip on a server's motherboard, often called the computer's brain, that does all the processing and calculations.
• RAM is the working memory used by your server's OS and applications.
• A disk is a storage where your servers are storing data.
• A network interface provides a network connection to and out of your servers.
• Rack-mountable servers are big servers that are mounted on a rack.
• Blade servers are small modules known as blades that are mounted on a server's chassis to save space.
• Tower servers are single servers that stand upright.
• The Start menu is returned in Windows Server 2016.
• The TechNet Evaluation Center is a web portal that provides the option to download and evaluate Microsoft's products free of cost.
• The Windows Server 2016 Datacenter is designed for enterprises that own highly virtualized data centers or act as cloud providers.
• Windows Server 2016 Standard is designed for medium-sized businesses that use servers on-premises to run their network services.
• Windows Server 2016 Essentials is designed for small businesses that run a single server in their IT infrastructure.

1. Windows Server 2016 is Apple's latest operating system for servers. (True | False)
2. The __________________ is a group of computers connected to each other in order to share resources.
3. Which of the following are computer network components? (Choose two)
   1. computers
   2. servers
   3. Master Boot Record (MBR)
   4. Basic Input/Output System (BIOS)
4. Resources can be data, network services, and peripheral devices. (True | False)

5. Which of the following are Windows Server 2016 editions? (Choose three)
   1. Windows Server 2016 Essentials
   2. Windows Server 2016 Standard
   3. Windows Server 2016 Datacenter
   4. Windows Server 2016 Enterprise
6. _________________________ is a web portal that provides the option to download and evaluate Microsoft's products free of cost.
7. Which of the following are servers size and format factors? (Choose two)
   1. Blade servers
   2. Tower servers
   3. Network printer
   4. Network switch
8. The Start menu is returned in Windows Server 2016. (True | False)
9. _____________ is any device that can generate, receive, and transmit the networking resources on the computer network.
10. Which of the following hardware components affect the performance of your servers? (Choose two)
    1. Processor
    2. RAM
    3. Printer
    4. Monitor
11. A server is a computer that requests resources in a computer network. (True | False)
12. ________________ networking is a computer network in which the participating computers do not have predefined roles in the network.