Introduction
Web Application:
The applications which will provide services over the web are called web applications.
Eg gmail.com, facebook.com, durgasoftvideos.com et Every web application contains 2 main components
1. Front-End
2. Back-End
1) Front-End:
It represents what user is seeing on the website
We can develop Front-End content by using the following technologies: HTML, JS, CSS, JQuery and BootStrap
JQuery and Bootstrap are advanced front-end technologies, which are developed by using HTML, CSS and JavaScript only.
HTML: HyperText Markup Language
Every web application should contain HTML. i.e HTML is the mandatory technology for web development. It represents structure of web page
CSS: Cascading Style Sheets
It is optional technology; still every web application contains CSS.
The main objective of CSS is to add styles to the HTML Pages like colors, fonts, borders etc.
Java Script:
It allows to add interactivity to the web application including programming logic.
The main objective of Java Script is to add functionality to the HTML Pages. i.e to add dynamic nature to the HTML Pages.
HTML===>Meant for Static Responses HTML+JS==>Meant for Dynamic Responses
Eg 1: To display "Welcome to ANITS" response to the end user only HTML is enough, because it is static response.
Eg 2: To display current server date and time to the end user, only HTML is not enough we required to use some extra technology like JavaScript, JSP, ASP, PHP etc as it is dynamic response.
Static Response vs Dynamic Response:
If the response is not varied from time to time and person to person then it is considered as static response.
Eg login page of gmail, home page of icici bank
If the response is varied from time to time and person to person then it is considered as dynamic response.
Eg inbox page of gmail, balance page of icicibank
2) Back End:
It is the technology used to decide what to show to the end user on the Front-End.
ie Backend is responsible to generate required response to the end user, which is displayed by the Front-End.
Back-End has 3 important components:
1. The Language like Java, Python, Node.js, Express.js etc
2. The Framework like Spring, DJango, Pyramid, Flask, Express.js etc
3. The Database like SQLite, Oralce, MySQL, PostgreSQL etc
In a MERN Stack application, the technologies can be mapped to the traditional layered architecture as follows:
HTML Basics:
HTML stands for HyperText Markup language.
This is the most basic building block of every web application. Without using HTML we cannot build web applications. It is the mandatory technology.
We can use CSS to style HTML Pages.
We can use Java Script to add functionality to the HTML pages.
Structure of HTML Page:
Every HTML page contains 2 parts
1. Head
2. Body
Head contains meta data like title of the page, keywords etc. CSS files and Java Script files information we have to specify in the Head Part only.
Body contains actual content.
A HTML page is a collection of html elements.
An html element is a combination of opening tag, content and closing tag.
HTML Element Syntax:
Content
index.html
