User Interface, commonly known as UI, has the dictionary definition of:
"the means by which the user and a computer system interact, in particular the use of input devices and software."
Basically, it’s the interface of the combination of hardware and software. But in our case, we are focusing on the software aspect.
User Experience, also known as UX, has the dictionary definition of:
"the overall experience of a person using a product such as a website or computer application, especially in terms of how easy or pleasing it is to use."
It’s the experience the user has when they are using the interface.
When designing a website, apps, etc. You need to understand how easy it is for the user to use the site, and how pleasing it looks to them.
We define UX as “How many steps does it take for me to go from point A to point B?”
We define UI as “How easy/aesthetic is it to go from point A to point B?”
Keep these terms in mind when designing your website. This will increase user count, engagement, and more.