Let's talk about back-ends.

What is Node?

Node is a JavaScript environment built on the same JavaScript engine used in Google’s Chrome web browser. It has some great features that make it an attractive choice for building server-side application middle tiers, including web servers and web services for platform APIs. The non-blocking event-driven I/O model gives it very attractive performance, easily beating threaded server environments like PHP and Ruby on Rails, which block on I/O and handle multiple simultaneous users by spinning up separate threads for each.

Node Features:

Fast! (Non-blocking I/O by default). Easy to get started.
Event-driven.
First-class networking.
First-class streaming API.
Great standard libraries for interfacing with the OS, filesystem, etc…
Support for compiled binary modules when you need to extend Node’s capabilities with a lower-level language like C++.
Trusted and backed by large enterprises running mission-critical apps. (Adobe, Google, Microsoft, Netflix, PayPal, Uber, Walmart, etc…).

What is Express?

It’s a minimalist and extensible web framework built for the Node.js ecosystem. It enables you to create a web server that is more readable, flexible, and maintainable than you would be able to create using only the Node HTTP library, which can get verbose and complicated for even the most basic web servers. Express is going to make creating a web server much easier! As a matter of fact, it’s difficult to even find examples of real-world web applications that use only the Node HTTP library because you’d have to be sadistic to do it.

Hello, World!

Node & Express are easy enough that you get a basic web server to serve “Hello, world!” in about 11 lines of code:
 

What is CRUD Operation?

The CRUD concept was not originally conceived as a modern way to create APIs. CRUD actually has its roots in database records. Most modern web and mobile applications contain some form of CRUD functionality. In addition, most programmers have to deal with CRUD at some point. So, a CRUD application would be one that utilizes forms to retrieve and return data from a database.

A relational database consists of tables with rows and columns. In a relational database, each row in a table is called a record, and each column in the table represents a specific attribute or field. Users can call four CRUD functions to perform different types of operations on selected data in the database. This can be done through code or through GUI. Now, let’s take a look at each function separately.

CREATE:

This feature will add a new student to the app/database by some trigger, for example, by pressing the “Add” button in the application, which will call the corresponding function. The program calling the function would supply the values ​​for “first_name”, “last_name”, and “course”. After the function is called, a new student record will appear in the database.

READ:

This function allows you to see if there is a record about a specific student in the database. This function does not change the information about the student in any way, but only allows you to get information about him. You can also see a certain attribute.

UPDATE:

It's a function that changes information about a student. Let’s write his name. After the function is applied, the corresponding record in the database table will be changed.

DELETE:

Of course, everything should be clear here. This function either completely removes the object or removes its selected attribute.

By definition, CRUD is more of a cycle than an architectural concept. There are several CRUD loops in any web application. For example, in an online store, a customer can CREATE an account, UPDATE account information, and DELETE items from the cart. At the same time, a store admin using the same web application can CREATE shipping records, READ them as needed, and UPDATE supply lists.