Masoud Alam

World Wide Web or Web was invented by Sir Tim Berners-Lee in 1989. Short for World Wide Web, the WWW, W3, or web is a graphical interface for the Internet that was first introduced to the public on August 6, 1991, by Tim Berners-Lee. A few days later on August 23, 1991, it was available to everyone. The World Wide Web, commonly known as the Web, is an information system where documents and other web resources are identified by Uniform Resource Locators, which may be interlinked by hypertext, and are accessible over the Internet. The resources of the WWW may be accessed by users by a software application called a web browser. Web consists of three key components: HTML – Hypertext Markup Language. This is a standard markup language used to create web pages. URL – Uniform Resource Locator. This is the understandable form of a web address which is used to identify a resource. HTTP – Hyper Text Transfer Protocol. This protocol is stateless and acts as the foundation of the Web.

A Uniform Resource Locator is the address of a resource on the Internet. A URL indicates the location of a resource. It is also referred to as a web address Uniform Resource Names are identifiers for resources. They are location independent. A URN is an Internet resource with a static name that remains valid even if its data is moved to another location. Unlike a URL, which cannot work if the content is moved, a URN is always able to track the resource of certain data on the Web, hence resolving a frequent issue of moving of data. A Uniform Resource Identifier can be a name, locator, or both for an online resource where a URL is just the locator. URL & URN are a subset of URI. That means all URL & URN are URI. All URLs are URI  but not all URIs are URLs because a URI could be a name instead of a locator. All URNs are URI  but not all URIs are URNs because a URN could be a locator instead of a name. A URN is similar to a person's name, while a URL is like a stree...