Selenium has four main components: Selenium IDE, Selenium RC, Selenium WebDriver, and Selenium Grid.
Selenium IDE is a Firefox plugin that you can use to record and playback tests. Selenium RC is used to write automated tests in any programming language. Selenium WebDriver is used to write tests in any programming language against any web application. Selenium Grid is used to distribute tests across multiple machines.
Other related questions:
How many components are there in selenium?
There are four components in selenium:
1. Selenium IDE
2. Selenium RC
3. Selenium WebDriver
4. Selenium Grid
What are the components of selenium suite?
What are the 4 components of selenium?
What are the three major components of selenium IDE?
The three major components of Selenium IDE are the IDE itself, the Selenium Core and the Selenium RC.