What is Selenium? A Complete Overview in 2021


What is Selenium? Selenium is a software suite and not just one tool in software testing. Each piece of software in this suite has a different quality analysis testing need it addresses in any organization. It comprises components like the Integrated Development Environment (IDE), WebDriver, Remote Control (RC) and the Grid. Selenium Version 1 is also referred to as the RC version, and when the framework used has WebDriver and RC components combined, it is referred to as Selenium Version 2. Let’s then begin this introduction to automation testing in the Selenium software tutorial.

In this article let us look at:

  1. Definition
  2. Birth of Selenium
  3. RC
  4. Selenium WebDriver, IDE, RC, Grid and comparison of Selenium over other tools
  5. Advantages

1. Definition

Selenium software is free-to-use (open-source) and is a framework of automated Selenium tools used in testing with different platforms and browsers in the validation process of web applications. Test Scripts using Selenium are also compatible with a host of languages like C#, Java, Python and more. Selenium automation testing is hence the process of testing using the suite tools of Selenium and defines what is Selenium testing.

2. Birth of Selenium

Being a set of Selenium components and testing tools, Selenium is a suite of different tools, having different developers. In 2004 Selenium was crafted by Jason Huggins. When working with web applications (at ThoughtWorks) needing testing frequently and realizing that manual testing was inefficient or cost-effective, he used Java to script an automated application controlling the testing browser, named the “JavaScript TestRunner.”

The application was usable across other web applications, and he made the script open-source. This script is also referred to as the Selenium Core. The name Selenium was used since it is used for alleviating Mercury poisoning. The same team also worked on the QTP (Quick Test Professional) automated testing framework application, later acquired from Mercury Interactive by the HP stable, and was just a joke on the Selenium meaning. 

However, due to the same-origin policy restriction by the Javascript codes, the testers needed to have the whole web-server and test-application downloaded and installed on their computers to have the same domain as expected of them by Javascript’s policy. That’s when another member of the team at ThoughtWorks came up with an application that sought to trick the same-domain origin policy of the Java browser by using a proxy server running on HTTP. This framework was called what is Selenium’s Remote Control version of Selenium, aka Selenium 1 or Selenium 

3. RC

With popularity growing, the need to reduce time constraints in test execution was addressed by Patrick Lightbody who named the system ‘Hosted QA’, which was able to take screenshots of simultaneous Selenium commands to networked machines and the process of testing in various crucial testing stages. This framework is what is Selenium’s Grid.

The Japanese Shinya Kasatani improved the testing process using a Firefox extension to playback-and record testing processes on the application and make the browser fully automated. This development reduced testing times further as the creation of test-cases speed was vastly improved. In 2006 the software was donated to the Selenium project and was presently what is Selenium’s IDE version. Also, in 2006, Simon Stewart created a cross-platform web-testing framework using OS-level controls to control the browser. This application is what is Selenium’s WebDriver.

By 2008, the Selenium Core application had become very popular, and the team decided to merge the applications of the Selenium suite’s RC and WebDriver to launch the vastly improved version, which uses the core of the WebDriver and also implements the RC version of Selenium, creating what is Selenium’s new Selenium 2. All changes are iterative, and now all eyes are on improving Selenium 2.

4. Selenium WebDriver, IDE, RC, Grid and comparison of Selenium over other tools


What is Selenium WebDriver? This tool suite has many advantages over the RC and IDE versions. It automates the browser, has a stable approach, and does not rely on automation testing on JavaScript. Rather control over the browser is through direct browser communication. It supports a host of languages like Python, Ruby, Perl, PHP, and Java and C #.


This tool suite or framework is easy for learners, and uses a Firefox extension as its plug-in. It is popular for prototyping, and its simplicity sees limitations in advanced cases of testing where one can use WebDriver or RC frameworks.


This framework and what is Selenium’s longstanding flagship framework addresses the need for a complete web-testing framework with fully automated tools. The latest v2.25.0 supports languages like Python, Ruby, Perl, PHP, and Java and C #, allowing the users to use their own preferences of these languages in running the RC testing suite.


The Grid framework was designed as Selenium’s tool and provided for parallel test execution when used with the RC framework. It works across different browsers, machines etc., simultaneously saving time and resources used in testing. It uses the nodes-and-hub concept where Selenium controls the hub to execute the application for testing across several nodes.

Comparison of Selenium over other tools:

In 2006, HP acquired the QTP test suite from the proprietary Mercury Interactive and was extremely popular in testing before Selenium revamped the testing scenario and how Selenium works. In comparison to QTP, which has limited add-on capabilities and is a close source application, the Selenium suite is open-source and extensible. 

Why Selenium? Selenium is versatile and depends on what is Selenium used for across its support for various OS, mobile devices. It also has the capability to run tests on a minimized browser. Whereas using QTP means one has to run tests in Windows, Chrome, Internet or Firefox. Besides its Android and iOS support for mobile automated tests application runs on the HP Mobile Center’s solution, and the test application supported with desktop visibility. The Selenium suite easily scores with parallel testing of Selenium examples since its competitors use paid-versions of parallel tests executed by HP’s Quality Center.

5. Advantages

Despite QTP’s capabilities which are far more advanced, the advantages of Selenium are widely preferred because of its- 

  • Cost factor where Selenium is free-to-use and QTP a paid version.
  • Flexibility in user languages with support over languages like Python, Ruby, Perl, PHP, and Java and C # whereas QTP runs on Windows, Chrome, Internet and Firefox only. It also scores in supporting other platforms and browsers.
  • Parallel Selenium testing tools can be deployed quite easily on Selenium in comparison to QTP’s capabilities that use the Quality Centre and a paid version for parallel testing. 

However, the advanced QTP has its own advantages that score over the limitations of Selenium, like both desktop and web applications, a built-in object-repository, IDE capabilities to automate faster, built-in local and global data tables, browser control access, capacity for test reports in other formats and customer support systems.


What is Selenium? Selenium framework suite is a popular, flexible and cost-effective way of automated simultaneous testing in parallel since it is an open-source suite with tools like RC, WebDriver and Selenium 2, which can be chosen depending on the needs of testing.

If you are interested in making a career in the Data Science domain, our 11-month in-person Postgraduate Certificate Diploma in Data Science course can help you immensely in becoming a successful Data Science professional. 



Related Articles

Please wait while your application is being created.
Request Callback