The evolution of Web Development, frontend and backend: Third edition

by Leon Gilyadov

A snippet from the The term hypertext was first coined by Ted Nelson in 1969 in his research project at Brown University. Hypertext is a text that is displayed on a computer monitor and has links to other texts. By clicking on a link, the user can navigate from one text to another. Ted Nelson developed a working prototype of an application that he called Hypertext Editing System on an IBM computer. Tim Berners-Lee, an English engineer in The European Organization of Nuclear Research (CERN) in Geneva, Switzerland, had an idea of the web in 1989. The idea was to make it easier for everyone in the world to create and share hypertext documents through the internet. To implement his idea, Berners-Lee invented a collection of a web browser, a web server, a protocol for communication between the browser and the server (HTTP), a language that annotates text to render the hypertext in the browser (HTML). A unique identifier for the hypertext document (URL). When the user types the URL in the browser, the browser sends an HTTP request to the server that hosts the website. The browser receives the HTML file as an HTTP response and renders the HTML in the browser. HTML is an acronym of Hypertext Markup Language. The syntax of HTML is similar to XML. For example, the following code makes a Here is a paragraph

. The HTML code can be written in any text editor. And when opened in the browser, the browser renders it. HTTP is an acronym of the Hypertext Transfer Protocol. HTTP defines a client (can be a browser) and a server and the communication between them. The client is sending a request message and the server returning an response message. The request message consists of the request line (the first line in the HTTP request message), request headers and an optional HTTP body. The response message consist of the status line (the first line in the HTTP response message), response headers, and an optional response body. The response body can be, for example, the content of an HTML file. The first line in the HTTP request message consists of a request method, a path, and an HTTP version. For “GET /homepage.html HTTP/1.1”. In this example, "GET" is the request method. It indicates that the request is for information retrieval. In the example, "/homepage.html" is the path, and "HTTP/1.1" indicates that version 1.1 of the HTTP protocol is used. The first line in the HTTP response message consists of HTTP version, status code, and the reason code. For example “HTTP/1.1 404 NOT FOUND”. In this example, “HTTP/1.1” indicates the version, 404 indicated the status, and “NOT FOUND” indicates the reason code.

39 pages, Kindle Edition

Published August 12, 2020