UX as the broad umbrella term: how it differs from the three technical articles
UX is short for "user experience". The term covers everything a person perceives, thinks and feels while using a digital product: from the first glance at a page to the moment they find, or fail to find, what they came looking for. It is a human, subjective concept, even though it can be observed and improved with method.
The term has a specific origin. In the early 1990s, cognitive scientist Don Norman worked at Apple with the job title "User Experience Architect", the first job title in history to use that phrase, though the abbreviation "UX" did not exist yet. From there the term spread across the entire digital industry to describe something bigger than the design of one screen: a person's complete experience with a product or service.
This is where it helps to separate the terms. Core Web Vitals, page speed and responsive design are technical, measurable building blocks within UX, not synonyms for it. Core Web Vitals measures load speed, responsiveness and visual stability with concrete numbers. Page speed is the broader term for load speed, of which Core Web Vitals is only the part Google turned into a measurable ranking factor. Responsive design is the development technique that adapts the same HTML to any screen size through CSS. All three describe technical aspects an automated tool can check.
UX, on the other hand, cannot be fully measured by an automated tool because it includes human judgment: whether a menu makes sense, whether the text builds trust, whether the user understands where they are and what they can do next. A page can pass all three technical articles linked above, load fast, avoid layout shifts and look good on a phone, and still have poor UX if its menu is confusing, its content is badly written, or it fails to build any trust with the visitor.
