Selenium IDE is one of the four basic components of Selenium itself, together with the Selenium Grid, the Selenium Remote Control (RC), and the WebDriver. Selenium IDE represents a software environment which allows the generation of automated test scripts. It stands for Integrated Development Environment. It is implemented as a plug-in for browser and works based on the principle of recording, playback, and saving your test scripts. Initially, this component was known as the Selenium Recorder. Today, Selenium IDE is an advanced tool used by millions of users around the world. Find out why you should learn how to use Selenium IDE today.
https://dzone.com/articles/a-complete-guide-to-learn-selenium-ide