A simple explanation of JavaScript is that it is a programming language that enables dynamic and interactive web experiences. It works alongside the CSS and HTML of a page and will most likely be behind anything that moves, refreshes or changes on your screen, such as a social media feed updating.

JavaScript can sometimes cause issues for search engine crawlers when the content of a page is inaccessible due to their inability to interact with the page, but when used correctly, it can enhance the user’s experience and create a page readable for search engines.