Browser, Explorer or HTTP Client

A web browser (commonly referred to as a browser) is a software application for retrieving, presenting and traversing information resources on the World Wide Web. If we give the browser an URL, it can bring a webpage from any part of the world.

HTTP Client

The Browser works together with a HTTP server, which is the program that stores web pages. The relation between these two programs is known as "Client-server", where the Browser is the client .

A client-server application is a distributed system consisting of both client and server software. The client process always initiates a connection to the server, while the server process always waits for requests from any client

They communicate through the "HTTP Protocol" and that is the reason why it is called "HTTP Client".

Note: most of the http clients can read files directly from a file system (CD, hard disk, etc.), without the need of a HTTP server.

HTML

The Browser receives a webpage, which is normally in HTML language. This HTML contains the text which we will see on the screen and the instructions as to how to organize the text. We can, for example, write part of a text as a title or as a link to another page. The Browser interprets HTML and displays on the screen the text following the instructions.

JavaScript

The webpage, can also contain JavaScript. This means that the page can include a program which runs in the client machine. In the past, these scripts were only used for small visual effects. It is now commonly used in AJAX.

Note: http://maps.google.com/ is the most famous example of AJAX.

Plug-ins

In computing, a plug-in (or plugin, extension) is a software component that adds a specific feature to an existing software application. When an application supports plug-ins, it enables customization. The common examples are the plug-ins used in web browsers to add new features such as search-engines, virus scanners, or the ability to utilize a new file type such as a new video format.

Flash

Probably the most important complement nowadays is "Adobe flash player". Flash is frequently used to add streamed video or audio players, advertisement and interactive multimedia content to web pages.

Java Applet

An applet is a small application that is placed inside the web page, which is not very used currently.

Summary

All of these tecnologies are known as "client side technologies". In the next tutorial we are going to learn about "server side technologies".

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