What is a server and how is it different from a normal computer?
In the world of computers and information technology. A server is a piece of computer hardware that provides the functionality for programs or devices, called clients. The actual architecture is referred to as the "client-server-model." Servers provide several functionalities that are often called "services", such as sharing resources or data among multiple clients. Or performing a computation for a single client. Just one single server can serve multiple clients. And just one single client can use the resources of multiple different servers. A client process might run on the same device or can connect over small or large computer network such as the internet to a server on a different device. Generally servers can be regarded as file servers, mail servers, database servers, print servers, game servers, application servers and web servers. And not to mention the servers that host and run the domain name system.
Client-server systems in our days are most frequently used by a model called the request-response model. This works by a client sending a request to a server which will perform an action and then it will send a response back the the client that requested it usually with a result or acknowledgment. Designating a computer as (server-class hardware) implies that it is specialised for running servers on it. A server is also regarded as more powerful and much more reliable than a normal standard computer and is always running 24/7. Alternatively, large computing clusters can be composed of several relatively simple, replaceable server components.
Server Hardware
The actual hardware requirements for different types of servers varies by a large value. Many servers will run completely unattended without the use of a computer screen, monitor or input device. They also generally do not have devices installed in them like audio hardware and sometimes without IO devices like USB interfaces. Just like a normal computer running windows. Many servers do not actually have a GUI otherwise known as a graphical user interface. Servers are also normally configured and managed remotely without a human standing in front of them. Remote management of these servers can be conducted using several different methods such as Microsoft Management Console, PowerShell, Browser based or SSH. Server systems designed by manufactures such as Dell use a special interface called iDRAC. And HPs version of this is called iLo for remote management.
Server Clusters
A server cluster or known as a server farm is a small or large collection of computer servers that is maintained by organisations in order to be able to supply server functionality that is normally far beyond the ability of a single device. Today, modern data centres are now built up of very large clusters of much simpler smaller servers and they all work together in a collaborative effort. This is an example of how Domain Registration DNS hosts their web servers for thousands of clients and websites.
Operating systems.
On the internet today the most dominant operating system or "OS" for short running on servers are normally Unix-like open-source distributions. Examples of these operating systems are Linux and FreeBSD. There is also a fair share of Windows servers although sometimes deemed not as secure. There are also proprietary operating systems out there such as macOS Server and z/OS. But these servers are in much smaller numbers at not used as often.
How many servers are there in the world?
Today. The internet now has at least 75 million servers worldwide. All connected together with approximately 550,000 miles of cables that all run under our vast oceans. These cables are transmitting data at around 186,000 miles per second with over 1 billion computers connected to it and rising to about 5 billion including all the other internet capable devices such as mobile phones and small tablet computers.
How many root DNS servers are there in the world controlling the internet?
Without the root servers. The internet would stop working over a period of a few days when data called cache starts to expire. There is known to be hundreds of root servers in different strategic locations all around the world. ICANN (internet cooperation for assigned names and numbers) is responsible for one the 13 root IP addresses that make up our DNS system and is intrusted with the operation of of the rest of the other 12 IP addresses to different organisations. Some of these organisations include NASA, Verisign and the Internet Systems Consortium.
What is a Web Hosting server?
A web hosting server is the term used for the type of server that hosts websites with their associated files, data, services and applications. It is a remotely accessible internet server with built in web server resources and functionality that runs websites and often email applications. A hosting server is also known to be called a web hosting or web server.
Types of hosting.
There are many different types of hosting servers out there and they are not just limited to web hosting or domain name servers. Here is a comprehensive list of different types of servers that host data, files and services.
Home Servers.
Cloud hosting servers.
File & print servers.
Grid hosting servers.
Reseller web hosting.
Shared web hosting servers.
Dedicated servers.
Virtual dedicated servers.
Clustered servers.
Windows servers.
Linux/Unix servers.
Email servers.
DNS servers.
Gaming servers.
FTP servers.
Time servers.
VPS servers.
Active Directory servers.
Exchange servers.
Co location servers.
Security servers.
Routing servers.
Artificial intelligence servers.
DHCP servers.
Distribution servers
Anti virus servers
Hyper-V servers.
ESX servers.
VMware servers.
Database servers.