The code files for the chapter can be found at https://github.com/PacktPublishing/NodeJS-for-Beginners.

The official definition of Node.js is very simple, but it doesn’t explain why Node.js has become so popular over time:

“Node.js® is an open-source, cross-platform JavaScript runtime environment.”

In Figure 1.1, we can see how the popularity of Node.js has been increasing over time, and even today, it is still growing fast.

Figure 1.1 – The interest in Node.js, generated using Google Trends

Next, let’s explore the main reasons why Node.js is so popular.

Lightweight and fast

Node.js is a lightweight and fast runtime based on the V8 JavaScript engine, which is the same engine that powers Google Chrome and Microsoft Edge, among others. It is based on a single-thread architecture and event-driven model, which means that it doesn’t need to create a new thread for each request, as in other popular tools such as PHP. This is a huge advantage because the memory consumption is...

When Node.js came out in 2009, it was a revolution in the web development world, as Ryan Dahl, the creator of Node.js, decided to use a very unusual approach at that time: a single-thread architecture.

In his presentation about Node.js at the JSConf (https://www.youtube.com/watch?v=EeYvFl7li9E), Ryan Dahl said he wanted to achieve two key things when building Node.js: server-side JavaScript and non-blocking I/O.

I/O needs to be done differently

The common approach for I/O operations in web applications is to create a new thread for each request. This is a very expensive operation because the memory consumption is very high and the performance is very low.

The idea behind this approach is to split the system resources and assign them to each thread. This is a very inefficient approach because, most of the time, the CPUs are idle, just waiting for the resources.

The other problem is that we are limited in the amount of memory that...

Node.js follows semantic versioning (SemVer) (https://semver.org/) and it is important to understand how this versioning works in order to choose the best version for the project.

Semantic versioning (SemVer)

When considering semantic versioning, it helps to determine what changes to anticipate as a user, especially whether they might cause disruptions or not. This understanding assists our end users in preparing for potential updates.

Semantic versioning is one of the most popular ways to version software. In the following figure, we can differentiate the elements used to build the release version.

Figure 1.3 – Parts of a semantic version number (source: Devopedia 2020, https://devopedia.org/images/article/279/2766.1593275997.svg)

When a new version is released, the version number is incremented following the SemVer rules:

• Major versions add incompatible API changes
• Minor versions add functionality in a backward...

In this chapter, we explored what makes Node.js so special and how it differs from other backend systems. We also covered the history of Node.js and how it has evolved over the years.

Additionally, we covered the Node.js architecture and how it works under the hood. We learned about the event loop and how it allows Node.js to handle many concurrent requests efficiently.

In the next chapter, we will learn how to set up the development environment and start using Node.js.

• Node.js governance: https://nodejs.org/en/about/governance
• OpenJS Foundation governance: https://openjsf.org/about/governance/
• The Life and Times of a Node.js Release, by Danielle Adams at NodeConf EU 2022: https://www.youtube.com/watch?v=OiSBodpU174
• Node.js dependencies: https://github.com/nodejs/node/blob/main/doc/contributing/maintaining/maintaining-dependencies.md
• Node.js event loop architecture: https://medium.com/preezma/node-js-event-loop-architecture-go-deeper-node-core-c96b4cec7aa4
• How Node.js Bootstraps Itself, 2019 edition, Joyee Cheung, Igalia: https://www.youtube.com/watch?v=bwiLlcGvFEk
• Node.js 12: A Decade of Node.js, Beth Griggs, IBM: https://www.youtube.com/watch?v=HP4N0u_dEgI
• Node.js 2023 Year in An Article: https://blog.rafaelgss.dev/nodejs-2023-year-in-review