Step by step guide to learn JavaScript in 2025
June 18, 2025JavaScript is a very flexible and versatile programming language, considered as a core technology for web development. This is because it is the only language natively supported by all browsers, allowing developers to add dynamic behavior and create complex user experiences with this language.
Because of its flexibility and portability, JavaScript is also widely used for back-end development (thanks to runtimes such as Node.js, Bun, and Deno) and even server-side scripting (for automation and for creating developer tools).
A JavaScript developer writes and maintains code to build interactive web applications, back-end logic (usually RESTful APIs), or some automation work.
If they're focused on front-end development, their work usually involves designing dynamic user interfaces and integrating them with REST APIs (usually) to connect with back-end systems.
If, on the other hand, they're focused on back-end development, then most likely, they're spending most of their time developing APIs using a back-end framework like NextJS.