Selenium is an automation testing tool, or more precisely, a framework. It is an open-source framework built for automated web application testing. Furthermore, Selenium is a versatile testing solution that enables automation testers to develop Selenium testing scripts in a variety of programming languages, including Python and Java.

The Selenium architecture consists of the following components:

  • Selenium IDE
  • Selenium RC
  • Selenium WebDriver
  • Selenium Grid

Now let us look at each of these components one by one. Check out our Selenium automation testing course to learn more.

Selenium IDE

Selenium IDE
The acronym Selenium IDE stands for Selenium Integrated Development Environment. Shinya Kasatani of Japan created it, and it was later developed further. Selenium IDE is a Firefox plugin that allows developers to record and playback their scripts. One of the benefits of Selenium IDE is that it requires no programming skills. Simply knowing HTML and DOM would be sufficient. The Selenium IDE is commonly used as a prototyping tool due to its simplicity.

Selenium RC

The meaning of RC in Selenium RC is Remote Control. It is frequently referred to as Selenium 1 because it was the first flagship testing framework and remained a popular web automation testing tool for many years. Selenium RC’s automation functions are based on Javascript. Selenium RC supports the following languages: Python, Perl, Ruby, Java, C#, and PHP. Selenium RC also supports practically all web browsers that are currently available. However, Selenium RC is now officially obsolete.

Selenium WebDriver

Selenium WebDriver
Selenium WebDriver is an automation framework that you can use to automate user actions. It also interacts with modern web browsers using a set of open-source APIs. Selenium WebDriver is implemented using a browser-centric driver.

Selenium WebDriver supports the following operating systems: Windows, MacOS, Linux, and Solaris.

Selenium WebDriver supports programming languages including Java, C#, PHP, Python, Perl, Ruby, and Javascript.

Selenium WebDriver supports the following web browsers: Mozilla Firefox, Internet Explorer, Google Chrome 12.0.712.0 and above, Safari, Opera 11.5 and above, Android, iOS, and HtmlUnit 2.9 and above.


Selenium WebDriver’s architecture includes the following:

1. Client Browser Drivers for the JSON Wire Protocol over HTTP (Selenium Client Library)

The Selenium Client Library includes language libraries for Java, Ruby, Python, and other supported languages.


JSON stands for JavaScript Object Notation. This Selenium WebDriver component is critical to the Selenium automation process since it transfers data between the server and a web-based client.

3. Browser Drivers

Browser Drivers
Browser drivers are used to facilitate communication between the Selenium WebDriver and the appropriate browser. Browser drivers ensure that no information about the browser’s core logic or functionalities is leaked to it.

4. Browsers

As previously stated, supporting browsers include Firefox, Safari, Chrome, and others.

Selenium Grid

This component of the Selenium suite works in tandem with the Selenium RC. It is used to execute parallel tests on machines and their associated browsers. Selenium. The functionality of Selenium Grid is dependent on the browsers and operating systems supported by the entire framework. Selenium supports practically all browsers and operating systems, making it easier for the Selenium Grid to run numerous tests concurrently against different machines using different browsers.

Why is Selenium so preferred?
You may already understand why Selenium is so popular based on the capabilities it provides and its architecture. Now, let’s look at why Selenium is the most popular automated testing framework.

Browser Compatibility

Selenium’s compatibility with practically all available browsers, including Firefox, Safari, Opera, and Chrome, making it a popular tool among automation testers and developers. Also, Selenium WebDriver’s cross-browser interoperability is the key reason it is preferred.


  • Language Compatibility
    Selenium provides significant freedom for writing code and testing scripts in a variety of languages. Testers cannot learn practically every programming language. Selenium’s all-language interoperability capability has made it a popular automated testing tool.
  • Prompt Implementation
    Automation testing is very fast due to the lack of reliance on intermediary servers. Communicating with browsers does not necessitate the use of middleware servers. Furthermore, the JSON is lightweight, which contributes to the rapid execution of automation testing.

Key Features of Selenium

Some of the key features provided by the Selenium suite are listed below.

  • Cross-Browser Testing: Selenium enables tests on the same website using the same scripts and codes across multiple browsers.
  • Parallel testing: It allows for the execution of scripts on one or more browsers at the same time.
    Modern Technology Support: Selenium allows all types of applications to be evaluated, regardless of the technology utilised.
  • Web Page Automation: Even web pages with dynamic content can be automated with Selenium.


To learn more about the Selenium Architecture, check out our Selenium online training.