1. It's an add-on that is only supported by the Firefox browser.
2. Selenium IDE brings one of the most valuable record and playback feature.
3. It is independent of the Selenium server to run the test script.
4. You may not use it to move mouse cursors.
5. You can readily use its record & playback feature.
1. It’s an API that supports Firefox, IE, Chrome, Safari, and much more.
2. It uses the Selenium server before processing the test script.
3. It’s a standalone Java (jar) application that runs Html test suites in the browser.
4. Its APIs are not fully object-oriented.
5.iPhone/Android applications are not supported.
1. It works with every browser like Firefox, IE, Chrome, Opera, and others.
2. You can’t use it for recording and playback.
3. It is a full-fledged API, and languages like Java, Python, and CSharp implement Webdriver APIs.
4. It allows for managing the movement of mouse cursors.
5. Selenium Server isn’t needed anymore to run the test script.
It is a standalone java program that allows you to run test cases written in a variety of programming languages with a variety of web browsers, and which can additionally run HTML test suites in a range of different browsers as it supports multi-browser compatibility, also choices like reporting. (My point is that the --HTML suite option of selenium-server.jar is not its primary function, and will soon be split out into a separate program.)
(Selenium IDE + Selenium RC + Selenium WebDriver + Selenium Grid)
Selenium 1.0 + WebDriver = Selenium 2.0
Microsoft Internet Explorer
With Selenium 2, you can write tests in Java, C#, Ruby, and Python.
Selenium 2 also offers a headless driver based on HtmlUnit, which is a Java framework for testing web applications. HtmlUnit is really fast, but it is not realistic as a driver associated with a real browser.