In this video.
Let's have a look at the road map for learning.
Express J is the first concept you need to know is what we call routing, and we will talk about it
as a Node.js developer.
We need to know how to implement routing in your application and after that you need to know what is
middleware.
Because Xpress is all about middleware and you use middleware for a lot of logic.
In our application, for example, we use middleware to implement what is called authentication, authorization
and business logic.
So when you say authentication, it simply means that allowing a user to enter into our application
and authorization simply means that after a user has logged in, what kind of action the user can take
inside our application, that's what we call authorization.
Again, we have a section for each of these concepts.
Now, what about the business logic?
Well, let's take this for example.
Let's say that we have a block application, and for block application we specify that a user can create
up to ten posts.
If you want to create more than ten posts, then you need to pay or subscribe to our payment plan.
So this is an example of business logic and application.
Or for example, if a user account is not verified, you need to send a message to the place, verify
your account before proceed.
So these are examples of use cases.
So we use middleware a lot.
So you dive in more to know what is middleware.
And after no matter what we are going to talk about is what you call error handling because you are
going to use the middleware concept to talk about how we can handle errors in our application.
So after knowing this, the next one is called template engine.
How we can pass dynamic data into a HTML.
Now that we know the Roadmap for learning experience in video, let's look at what is import and export
because we are going to import express from NPM and then we export our own function to be used in any
part of our application.