The word engine and execution engine are two terms that we will use a lot throughout this tutorial.
The engine or the execution engine is basically a general name we use to refer to the application in the browsers that is in charge of executing the JavaScript programs that developers write.
For example in the Chrome browser, the exact name of the execution engine that runs JavaScript programs is: V8.
In the table below you can see the exact name of the execution engine in other popular web browsers:
| Web Browser | Engine |
|---|---|
| Safari | Nitro |
| Google Chrome | V8 |
| Mozilla Firefox | Spider Monkey |
| Microsoft Edge | Chakra |
| Microsoft Internet Explorer | Trident, Chakra |
So in this tutorial, anytime you saw the word engine or execution engine remember that we’re referring to the application that is going to execute the JavaScript source code.