what is const express = require('express')

const express = require('express') is a line of code commonly used in Node.js applications to import the Express module and assign it to a variable named "express".

Here is an explanation of each step involved:

1. The keyword "const" is used to declare a constant variable in JavaScript. A constant variable cannot be reassigned once it has been defined.

2. "express" is the name chosen for the variable that will hold the imported Express module.

3. The "=" operator is used to assign the value of the imported Express module to the variable "express".

4. The "require()" function is a built-in Node.js function that is used to import external modules or files. In this case, we are using it to import the Express module.

5. Inside the "require()" function, we pass the string 'express' as an argument. This string represents the name of the module we want to import, which in this case is the Express module.

To summarize, the line of code const express = require('express') is used to import the Express module and assign it to a constant variable named "express" in a Node.js application.