A server is a computer or system that provides resources, data, services, or programs to other computers, known as clients, over a network. In theory, whenever computers share resources with client machines they are considered servers. There are many types of servers, including web servers, mail servers, and virtual servers.

A web server is a computer that runs websites. It's a computer program that distributes web pages as they are requisitioned. The basic objective of the web server is to store, process and deliver web pages to the users. This intercommunication is done using Hypertext Transfer Protocol (HTTP).

A web address is a unique name that identifies a website on the Internet. Web addresses are also known as URLs (Uniform Resource Locators). A web address consists of two parts: a protocol and a domain name.

In order to communicate with a web server and retrieve a web page, a web browser needs to know the web address of the web server. A web address consists of two parts: a protocol and a domain name. The protocol tells the web browser how to communicate with the web server. The domain name tells the web browser where the web server is located.

IP stands for Internet Protocol. It is a set of rules that governs the communication between any two devices on the Internet. Every device on the Internet has at least one IP address that uniquely identifies it from all other computers on the Internet.

An IP address is a unique string of numbers separated by periods that identifies each computer using the Internet Protocol to communicate over a network. An IP address consists of four numbers (each between 0 and 255) separated by periods. Each number can be zero to 255. For example,

• 8.13.156.7: IPv4 each number is between 0 and 255, separated by dots.
• 2001:0db8:85a3:0000:0000:8a2e:0370:7334: IPv6 each number is between 0 and 65535, separated by colons. => IPv4 is out of IP address, so IPv6 is created. Same principle applies.

DNS stands for Domain Name System. It is a system that translates domain names to IP addresses. DNS is a hierarchical decentralized naming system for computers, services, or other resources connected to the Internet or a private network. It associates various information with domain names assigned to each of the participating entities.

• User can not remember IP address, so DNS is created to help user remember domain name.
• DNS is like a phone book for the Internet. When you type a web address in your browser, the browser looks at the DNS to find the website's real address before it can retrieve the website.
• DNS maps domain names to IP addresses, looking up the IP address of a domain name is called a DNS lookup.
• Normally, DNS is provided by ISP (Internet Service Provider). However, user can change DNS provider to improve performance or security.

There are some DNS providers:

• Google
• Cloudflare
• OpenDNS