What are UX and UI? The Difference Between UX and UI Design

In the digital era, where every application promises a “top-notch experience,” distinguishing between UX and UI can sometimes feel as tricky as picking the right exit in a basement parking lot. Both are essential components of digital product design, but each “character” has a very distinct role. If UX is the “architect” silently crafting a smooth user experience flow, then UI is the “fashion designer” dressing the product in an appealing outfit. One focuses on how enjoyable it is to use, the other on how captivating it looks — and the truth is, lacking either one can leave your product… functional but unused, or easy to use but no one wants to touch it.

1. What is UX? (User Experience – Trải nghiệm người dùng)

UX (User Experience) tập trung vào cảm giác, trải nghiệm và sự hài lòng của người dùng khi tương tác với sản phẩm. Mục tiêu của UX là đảm bảo sản phẩm không chỉ hoạt động đúng, mà còn dễ sử dụng, trực quan và mang lại trải nghiệm mượt mà, hiệu quả cho người dùng.

What is UX? (User Experience – Trải nghiệm người dùng)

UX (User Experience) focuses on the feelings, experience, and satisfaction of users when interacting with a product. The goal of UX is to ensure the product not only works correctly but is also easy to use, intuitive, and provides a smooth, efficient experience for users.

Detect bugs earlyUX – or User Experience – is the overall experience a user has when interacting with a product, from the very first moment to when they leave. It’s not just about “can I use it?” but also “do I enjoy using it?”.
The goal of UX is to create a smooth, intuitive, and needs-focused journey that makes users feel: “Wow, my destiny…:))”

1.2. Role

Improves usability: UX ensures everything is arranged logically so users don’t have to… fumble through a mess.
Solves real-world problems: If the product doesn’t help users achieve their goals quickly, UX will find ways to improve it.
Affects emotion and loyalty: Good UX makes customers want to return, while bad UX… makes them run for the hills.

1.3. Key Elements of UX

User Research: Understand users’ needs, behaviors, and pain points.
Information Architecture: Organize information logically so users don’t get “lost” in the menu.
User Flow: Map out logical steps to complete a task.
Prototyping and Usability Testing: Create trial versions and let users “test” them before the official launch.

1.4. UX Design Process

The UX design process usually follows these steps:

Understand the problem & define goals
- Clarify business requirements and the problems that need to be solved for users.
Clarify the business requirements and the problems that need to be solved for users.
- Collect qualitative and quantitative data through interviews, surveys, and behavior analysis.
Analyze & develop strategy
- Create personas, journey maps, and identify core features.
Design wireframes & experience flows
- Create IA, user flows, and wireframes to shape the product structure.
Create prototype
- Simulate the product to test ideas before development.
Usability Testing & Improvement
- Give the prototype to users for experience, collect feedback, and optimize.
Hand over to UI & Development
- Transfer all documents, wireframes, prototypes, and guidelines for implementation.

💡 Important point: UX Design is not a one-way process; it often involves continuous iteration to optimize the product over time.

2. What is UI? (User Interface – User Interface)

2.1. Definition

UI – or User Interface – is the part that users actually see and interact with directly on the screen. In other words, UI is the “outfit” that the product wears when it meets the user.
The goal of UI is to create an attractive, clear, and easy-to-use interface, so users immediately feel “I choose you…!!”.

2.2. Role

The bridge between humans and technology: If UX is the blueprint of a house, then UI is the front door, the paint color, and how you arrange the furniture.
Expresses brand & aesthetics: Colors, fonts, images… help the product have its own personality and leave a lasting impression on users.

2.3. Key Elements of UI

Colors: Create emotions, brand recognition, and sometimes… influence behavior (e.g., red evokes urgency).
Typography: Choose appropriate fonts to make information easy to read and convey the product’s “character.”
Layout: Arrange elements logically so users’ eyes move naturally, without needing a “magnifying glass” to find a button.
Icons, buttons, images: Make the interface intuitive, allowing users to understand functions immediately without… reading instructions.
…

2.4. UI Design Process

Receive information from UX
- Receive wireframes, prototypes, user flows, and guidelines from the UX team.
Research brand & style
- Define colors, fonts, tone & mood, and brand identity elements.
Design Style Guide / Design System
- Create a set of standards including colors, typography, icons, buttons, spacing, and grid to ensure consistency.
Design static interfaces (Static UI)
- Draw screens based on wireframes, ensuring layouts are visually appealing, aesthetic, and easy to use.
Design Interactive UI
- Add hover effects, transitions, and animations to enhance interactivity and guide users.
High-Fidelity UI Prototype
- Create a high-detail prototype that closely simulates the real product.
UI Testing
- Check the clarity of icons, font sizes, color contrast, and usability across multiple devices.
Hand over to Developer
- Use tools like Figma, Zeplin, or Adobe XD to hand over design files along with technical specifications (specs).

💡 Key point to remember: UI Design is not just about aesthetics but also ensuring usability and consistency throughout the product.

3. The Difference Between UX and UI

Criteria	UX (User Experience – User Experience)	UI (User Interface – User Interface)
Definition	It is the process of optimizing the entire experience of users when interacting with a product or service.	It is the process of designing the visual surface and how users directly interact with the product.
Main goal	Help users complete tasks easily, quickly, with minimal confusion, and feel satisfied.	Make the interface visually appealing, attractive, consistent, and easy to recognize as a brand.
Scope of influence	Covers the entire experience before, during, and after users interact with the product.	Focuses on the display and interaction directly on the screen or device.
Execution sequence	Usually precedes UI: research – analysis – ideation – testing – optimization.	Follows UX: applies visual design based on the UX framework established.
Main tasks	– User Research – Analyze behaviors and needs – Build User Personas & Customer Journey Maps – Create User Flows – Design Wireframes – Conduct Usability Testing	– Choose colors and create color schemes – Select fonts (Typography) – Design icons, buttons, and images – Build a visually appealing layout – Add effects and animations – Ensure visual consistency
Required Skills	– Analytical thinking & problem-solving skills – Research and user interview skills – Understanding of user psychology – Knowledge of Information Architecture – Ability to test and continuously improve	– Good visual aesthetics – Knowledge of graphic design principles – Proficient in using UI design tools – Understanding of color theory and layout principles – Intuitive and creative thinking
Popular Tools	– Figma (for wireframing) – Miro / Whimsical (for mapping) – Google Analytics / Hotjar (for behavior research) – Maze / Lookback (for testing)	– Figma, Adobe XD (for interface design) – Photoshop, Illustrator (for graphic design) – After Effects / Lottie (for animations)
Deliverables	– User persona – Customer journey map – User flow – Wireframe – Usability testing report	– Complete interface (mockup, prototype) – Style guide / design system – Icon set, images, color palette
Desired Outcomes	Users can easily achieve their goals with minimal obstacles and enjoy a smooth experience.	The interface is attractive, engaging, and creates a professional yet friendly impression.
An attractive and engaging interface that feels professional and user-friendly.	Ride-hailing app: UX ensures that booking a ride is simple, steps are clear, and timing is displayed accurately.	UI determines the button color for “Book Ride” to be prominent, the map to be intuitive, and the driver’s image to be clear.
Importance	Determines the level of user satisfaction and their likelihood to return.	Determines the first impression and the level of user engagement.

4. The Relationship Between UX and UI

UX (User Experience) and UI (User Interface) are two inseparable pieces in digital product design. They do not compete but rather complement and enhance each other’s value:

UX ensures the product is easy to understand, easy to use, and meets the right needs. It is like the “infrastructure” and “structure” inside — how everything works, the steps users go through, and the feelings they get.
UI ensures the product is visually appealing, engaging, consistent, and easy to interact with. It is like the “exterior” and “decoration” — colors, fonts, layout, buttons, icons, images…

4.1 When there is only a beautiful UI but poor UX

Imagine an e-commerce application:

Bright colors, clear product images, modern fonts → Beautiful UI.
But when making a purchase, you have to go through 7 steps, a long and complicated form, with no related product suggestions → Poor UX.

Result: Users find it beautiful, but… abandon their shopping cart midway.

4.2 When there is only a beautiful UI but poor UX

Imagine an e-commerce application:

Bright colors, clear product images, modern fonts → Beautiful UI.
But when making a purchase, you have to go through 7 steps, a long and complicated form, with no related product suggestions → Poor UX.

Result: Users find it beautiful, but… abandon their shopping cart midway.

4.3 When UX and UI are well integrated

For example, a successful food delivery app:

UX: The ordering process is simple (search → select → pay in just 3 steps), with food suggestions, diverse payment options, and clear order status notifications.
UI: Colors that stimulate appetite, appealing food images, clear CTA buttons, easy-to-read fonts, and intuitive icons.

Result: Users enjoy opening the app and want to return next time.

Conclusion: UX is how the product works and delivers value, UI is how the product presents that value. A successful product needs both to work in harmony, like a piece of music that has both the right notes (UX) and a beautiful melody (UI).

5. Conclusion

UX (User Experience) is the overall experience of a user when interacting with a product, focusing on making the product easy to understand, easy to use, and meeting needs.
UI (User Interface) is the visual display of the product, focusing on being attractive, clear, and engaging.

Key difference:

UX focuses on how the product works.
UI focuses on how the product is presented.

Although they have different roles, UX and UI must work harmoniously together. A product that is only beautiful but difficult to use will quickly lose customers, and conversely, a product that is easy to use but has a poor interface will struggle to make a good first impression.

💡 Tip: To design well, understand the users to build a proper UX, and at the same time, know how to present it to make the UI attractive. Simply put: “Don’t just make the product beautiful, make it both beautiful and useful.”