User experience (or UX) is a term developers use to describe how your customers interact with your software.
I’m sure you’ve used a website or an app before and been bamboozled or frustrated – this is an example of bad UX. Conversely, as well as simply delivering functionality to your users, good UX will go that extra step to make your software a delight to use.
https://www.cio.co.nz/article/641348/user-experience-just-pretty-fluff/