A web application is set of resources which will be available in universally. Resources are like files, images and any data which is informative.
Each web application has its own unique location in the internet so that we can access the web application.
To represent any web application in internet we will use domain or IP address this is called address of application. This address is unique in the web world or internet which gives you the destination point of web application.
When we talk about web application we need to consider two things that are Server and Client.
As we know web application have destination point these destination point is server. Server is one kind of software which manages the web application. A client is requesting for server to get response from server.
Web application is implemented by Client Server Architecture.
Client Server Architecture:
Client server architecture is working based on request and response mechanism. Client is always request for the server to get response. The response is like file, images or data.
We know response is generated by server and request is send by client.
What is client in real world?
In internet world a client is software which is able to send request to the server. Once it gets server response it should able to view the response to real world. Here we can say client is able to view the response and response consist of images, files and data.
In web application world a client is web browser. We are very familiar with web browser so some web browsers like Internet Explorer, Mozilla Fire Fox and Chrome.
So the bottom line is client is web browser that can send request to server and it can view the service response to out side world.
What is server in real World?
A server is also software which manages the web application that means it is managing resources. It is always serving the response to the client when client sends request to server. We have many servers in real world like Apache server, Tomcat Server and JBoss server.
Well we understand server and client.
Client Server Communication
We are talking client sends request and serve will give the response to client. How the request will be sent to server and how response will be reached by client.
We need a language that should communicate client and server. That language should understand by both server and client.
This language is called HTTP. Http is mechanism which will used to communicate client and server.
Hyper Text Transfer Protocol (http) is making the communication between client and server and it has some set of rules that will be followed by client and server.
In the real world http is like URL it represent the client request. Http can understand by only client that’s web browser and server.
Whenever client needs some resource or data it will send his request in the form of URL. This URL request can be understand by server so that it will send required response to the client based on what client is looking for.
Each URL request has some parameters these parameters will be decide what kind of response should be generated by server.
How client can display response?
In web world client is web browser how do browser can view the server response, here we need some specialize language that should be understand by browser the language is called HTML.
HTML is way of view the response in browser. The browser can understand only one language called Hyper Text Markup Language (HTML) so that server which is going to send to the browser should be HTML format.
Apart from HTML browsers can display different format data like images, PDF and some file formats. The default response format is always HTML format.
What is HTML?
HTML is specialize language for web browsers. It is tag based language it have many tags to display data in browsers.
The more about HTML go through following link
Html is just tag based language it only show the content in the page but if we want perform some actions or events in the browser it will use another language that is called scripting language.
Scripting languages are specialize languages for browser so that we can perform some actions and events in the web page.
Java Script is very popular scripting language for the web browsers.
The following link will give more information about java script
We already know HTML can view the response in browser to real world people. The data which we displayed in the browser need some styles or colors so that it will be better look and feel to people.
To make content beautiful in the browser we need some other language that is called Cascading Style Sheets (CSS)
CSS will give better look and feel to the data so that I will be attractable.
The following is more about CSS
The bottom line is the response is in the form of HTML and html data need some other languages support to make content beautiful and perform some action in browser for this reason we need another languages like CSS and Java Script.
Well we have good understanding about web application and it working in real world.
In real world web application can categorized in two types
- Static Web Applications
- Dynamic Web Applications
We will discuss more in the next part of my articles