The debates over the definitions of UX and UI have been going on for almost as long as the terms
have been around. UX stands for User Experience, and UI stands for User Interface.
Clear as mud? That probably did not produce a lightbulb moment of understanding. How the
end-user interfaces with something impacts their experience of the product, right?
It does not help that the terms were not coined at the same time. That is undoubtedly one of the
reasons why there is so much confusion surrounding them. They were not clearly defined at
inception because they were not simultaneously conceived. The term User Interface came first –
around the same time computing was brought to market.
Fast forward to the 90s when Don Norman helped coin the term User Experience while working at
Apple. At the UX Conference in San Francisco, he explains in a video interview that UX is about
the entire experience that the user has with the product, the company, and the services.
Everything from the way customer service is perceived to how easily the product is released from
So where does that leave User Interface? Depending on whom you ask, UX and UI are either
wholly separate, or they overlap, or UI is a subset of UX. How you define UX has a significant
bearing on the perspective of the two terms.
One school of thought separates the terms like this:
Think of a house. The framing of the house is the physical structure – the coding. The electrical
system and the plumbing and the HVAC are the functionality of the house – the user experience.
The window hardware, doorknobs, faucets, and paint are how the homeowner interacts with the
house and their enjoyment of it – the user interface.
In that example, the two are separate entities. They rely on each other, but there is little overlap. If
UX design only relates to the functionality of the house, then UX design would need to come first,
and UI design would wait to step in after UX was completed.Another philosophy subscribes to the
concept that UX is the whole enchilada – starting while the house design is still being conceived
and moving fluidly through all components of building and delivering the house to the buyer or
developer. In that scenario, UI design either overlaps or acts as a subset by handling the end-
user interface of the faucets as part of the UX design project.Here is what can be agreed on with
How much does this matter? It can matter a lot.
A small firm desiring in-house UX and UI may be looking for one person to do both and end up hiring a UI designer who does not have the UX skill set or vice versa without a clear understanding of what the two terms mean, someone wanting a website might end up hiring a firm that does not offer all the services they need or does not have the expertise to create what they are looking for.
Clearly, there is a practical need to understand the two terms. Paying attention to the UX and UI
design of your product can make or break the success of a product or service.
Since Don Norman helped coin the concept of the user experience, it would be easy to accept
his definition as gospel. However, it was about 20 years ago that the concept of user experience
was born, and language, technology and the workforce have evolved a great deal since then.
Definitions require context, and the context of defining these terms is present day. Academia is a
good place to start to clarify what the terms mean now. What are people being taught to become
UX designers and UI designers?
Course outlines for UX and UI design programs at Career Foundry illustrate the key responsibilities of each position.
UX Designer Key Responsibilities
Prototyping and Wireframing: Prototyping, Testing/Iteration, Development, Planning, Wireframing
Analytics and Execution: Coordination with Developer(s), Coordination with UI Designer(s), Analysis and Iteration, Tracking Goals and Integration
UI Designer Key Responsibilities
Look and Feel: Branding and Graphic Development, User Guides/Storyline, Customer analysis, Design Research
Responsiveness and Interactivity: Adaptation to All Device Screen Sizes, Interactivity and Animation, Implementation with Developer, UI Prototyping, Implementation with Developer
Despite the philosophical similarities, practical application in the marketplace is very different.
The three primary differences between UX and UI designers are:
1.UX deals with the purpose and functionality of the product. UI deals with the quality of
the interaction that the end-user has with the product.
2.UI design has an artistic component as it relates to the design and interface with the
product. It affects what the end-user sees, hears, and feels. UX has more of a social
component for market research and communicating with clients to understand what their
3.UX focuses on project management and analysis through the entire phase of ideation,
development, and delivery. UI has more of a technical component to produce the design
components for the finished product.
UX and UI are not areas to skimp on. Regardless of the definitions and division of labour, they are
both essential parts of product development and delivery. Research shows that customer
experience drives revenue growth. UX and UI are an investment in the product or service. The
product or service is what customers are spending money on. If spending their money does not
reap the reward they are looking for, they will shift their investment to a product that does.
Whether a company is being sourced or an employee being hired, it is essential to keep in mind
that both UX and UI theories and practices are dynamic in the marketplace. The question needs
to be asked: How do you stay abreast of the current UX and UI theories and practices? The
answer should come quickly and easily if they are engaging in any form of continuing education.
Keep in mind that these terms are still used interchangeably, and that is not likely to stop anytime
soon. Do not assume that the terms are being used correctly by the person using them. Even if
the person is an expert in the field, he or she may have a different philosophy regarding the
division of labour between a UX and UI designer. Drill down to gain clarity. The real goal is finding
out what they want. There is no need to prove people wrong or argue semantics. Language is
about understanding each other. If you understand each other, that is all that matters, and both UI
and UX rely on the efficiency of understanding.