1] How does JavaScript work? In most instances, JavaScript is known as a client-side script. That means it relies heavily on the client device, such as a tablet or smartphone, to run properly.

Asynchronous programming in JavaScript leverages features like callbacks, promises and async/await to sidestep this issue by allowing other code to run in the meantime.

Love it or loathe it, JSX has made a big impact on front-end engineering. Here's a code-first intro to the HTML-based JavaScript templating language.