Express.JS is a Node.JS web application server framework, designed for building single-page, multi-page, and hybrid web applications. It is the de facto standard server framework for Node.JS. There are several popular Node.JS frameworks that are build on Express:
1- LoopBack: Highly-extensible, open-source Node.JS framework for quickly creating dynamic end-to-end REST APIs.
2- Sails: MVC framework for Node.JS for building practical, production-ready apps.
3- Kraken: Secure and scalable layer that extends Express by providing structure and convention.
Express adds dead simple routing and support for connecting middleware, allowing many extensions and useful features like web page sessions, POST body /query string parsing, easy templating through jade, mustache, etc, and graceful error handling that will not cause the entire server to crash.It is advisable to consult with an IT career counselor to understand what career options best fits your skills. For instance, if you want to be a software engineer, learning HTML and CSS might not fit the bill. Here is an excellent article for learning more on coding and technology career roadmap. Once you know what career path you wish to pursue, you can make a plan on what, when, and how to learn. There are lots of online resources for learning coding and technology in general. For teenagers and high school students, High School Technology Services offers variety of hands-on training. For adults and professionals, Coding Bootcamps and DC Web Makers Companies offer basic to advance project-based programming and technology classes.