JavaScript is a high-level programming language, specifically functional and imperative, prototype-based, and object-oriented language. It was created in 1995 in 10 days by Netscape programmer Brandan Eich, amid the browser wars between Microsoft and Netscape navigators.

The language was designed as a lightweight scripting language to support HTML. Additionally, in 1997 it became an ECMA-262 standard. All these events allowed JavaScript to succeed in the client-side of web development.

In 2009, Ryan Dahl created Node.js, which alongside Googles v8 engine made JavaScript available as a server-side solution. At the time, softwares built with blocking I/O and using threads to handle concurrent requests, like Apache HTTP Server, was the common solution, which either blocked the processes or required multiple execution stacks. Meanwhile, JavaScript's single-threaded design had pushed its community to develop asynchronous solutions. Combined with a non-blocking I/O and the creation of the package manager npm in 2010, Node.js became a popular solution for server-side applications.

Still today, JavaScript is considered a core technology of web development with 97% of websites using JavaScript on the client side. In addition, it also took a considerate market share on the server side since Node.js introduction.