For designers & developers
The ultimate UX glossary.
122 terms, explained in plain language, with where each one comes from and what it looks like in practice. Free to use, free to link to. If a term is missing, tell me and I'll add it.
A
- A/B testing Randomly splitting live traffic between two versions to measure which performs better on a chosen metric.
- Above the fold / Below the fold The part of a page visible before any scrolling, and everything that needs scrolling to reach.
- Accessibility Designing so that people with disabilities can perceive, understand, navigate and use a product.
- Adaptive design Serving one of several fixed layouts based on the detected device, rather than one layout that flexes.
- Affinity diagram Grouping individual research observations by similarity until the themes emerge from the data.
- Affordance What an object or control offers the user, and how much of that is visible from looking at it.
- Agile Building software in short cycles that deliver working increments, rather than specifying everything up front.
- Agile UX Practising user-centred design inside Agile delivery, usually by running research and design slightly ahead of build.
- Android Google's mobile operating system, and the platform conventions that come with designing for it.
- API The defined way one piece of software talks to another, and a real constraint on what an interface can show.
- Atomic design A way of structuring a component library in five levels, from the smallest elements up to full pages.
- Avatar A small image or initials standing in for a person, used to identify who did what.
B
- Backlog The ordered list of everything a team might build next, with the most important work at the top.
- Beacon A small Bluetooth transmitter that lets an app detect roughly where a device is indoors.
- Beta testing Releasing a near-finished product to a limited real audience to find what internal testing missed.
- Brainstorming Generating many ideas before judging any of them, usually with a group.
- Brand identity The visible and verbal system that makes an organisation recognisable and consistent.
- Breadcrumb A trail showing where the current page sits in the site hierarchy, with each ancestor clickable.
- Breakpoint A viewport width at which a layout changes, usually because the current arrangement stops working.
- Bug Software behaving differently from how it was specified to behave.
C
- Call to action The control that asks the user to take the next step, and the words on it.
- Card sorting Asking users to group and label content so the structure reflects their model rather than the org chart.
- Chatbot A conversational interface answering questions or performing tasks through dialogue.
- Clickstream The recorded sequence of pages and actions a user moves through, in order.
- Cognitive load The mental effort a task demands, and the fact that working memory has a hard limit.
- Commit A saved, described snapshot of changes in version control, and the unit teams review and revert.
- Contextual inquiry Watching someone do their real work in their real environment, and asking about it as they go.
- Contrast ratio The measured difference in relative luminance between two colours, and the basis of WCAG text requirements.
- Conversion rate The proportion of people who complete a defined action out of those who could have.
- CSS The language that controls how HTML is presented: layout, colour, type, spacing and motion.
- Customer experience The whole relationship a person has with an organisation, of which the product is one part.
D
- Dark pattern An interface deliberately designed to trick users into decisions they did not intend to make.
- Design debt The accumulated cost of design shortcuts: inconsistencies and one-off patterns that make every future change harder.
- Design sprint A time-boxed process, classically five days, from problem to tested prototype.
- Design system The components, tokens, patterns and rules a product is assembled from, kept in sync between design and code.
- Design thinking A problem-solving approach that starts from user needs, works through prototypes, and iterates.
- Design token A named design decision stored as data, so one value drives both the design tool and the code.
- Diary study Asking participants to record their own experiences over days or weeks, capturing what a single session cannot.
- Double Diamond A design process model with four phases: discover, define, develop, deliver, alternating divergent and convergent thinking.
E
- Empty state What a screen shows when there is nothing to show, which is often the user's first impression.
- End user The person who actually uses the product, who is often not the person who bought it.
- Error message What the system says when something has gone wrong, and one of the cheapest things to fix well.
- Ethnographic research Extended observation of people in their own environment, to understand behaviour in its real context.
- Eye tracking Measuring where people look and for how long, usually visualised as heat maps or gaze paths.
F
- Feedback The system telling the user that something registered, what is happening, and what the result was.
- Fitts's Law The time to hit a target depends on its distance and its size: near and large is fast, far and small is slow.
- Flat design A visual style stripping away shadows, gradients and texture in favour of solid colour and clear type.
- Flowchart A diagram of a process as steps and decisions, used to make branching logic reviewable.
G
H
- Heat map A visualisation of where attention, clicks or scrolling concentrate on a page.
- Heuristic evaluation Experts reviewing an interface against established usability principles to find problems without recruiting users.
- Hick's Law Decision time grows with the number of choices, logarithmically rather than linearly.
- Human Interface Guidelines Apple's platform design documentation, defining the conventions expected of apps on its operating systems.
- Human-centred design Designing from the needs of the people who will use the thing, formalised internationally in ISO 9241-210.
- Human-computer interaction The academic field studying how people use computing systems, and the source of most of UX's evidence base.
- Human-machine interface The controls and displays through which a person operates a machine, especially where mistakes are physical.
I
- Inclusive design Designing for the full range of human diversity, so fewer people are excluded in the first place.
- Information architecture How content is organised, labelled and navigated, so people can find what they came for.
- Information scent How strongly a link or label signals that following it leads toward what the user wants.
- Interaction design Designing how a product behaves: what it does in response to input, over time, in every state.
- iOS Apple's mobile operating system, and the platform conventions expected by everyone using an iPhone.
- Iterative design Designing in repeated cycles of build, test and refine, rather than attempting to get it right once.
J
K
L
M
- Material Design Google's design system, defining components, motion, elevation and theming across its platforms.
- Mental model The user's internal understanding of how a system works, which is usually simpler and often wrong.
- Microcopy The small text that does the heavy lifting: labels, hints, errors, empty states, button text.
- Miller's Law Working memory holds about seven items, plus or minus two, and the figure is routinely misapplied.
- Mobile-first design Designing the smallest screen first, then adding for larger ones, so priorities get decided rather than inherited.
- Mockup A high-fidelity static representation of a design, showing what it looks like but not how it behaves.
- Motion design Using movement to show what changed, where something came from, and whether the system heard you.
- MVP The smallest version of a product that produces validated learning about whether the idea works.
N
O
P
- Persona A research-based description of a user type, used to keep design decisions anchored to real people.
- Pixel The smallest addressable unit of a display, and a unit whose meaning in design has drifted from the hardware.
- Progressive disclosure Showing what is needed now and deferring the rest, so complexity is available without being constant.
- Prototype A working approximation built to answer a question, at the lowest fidelity that answers it.
Q
R
S
- Screen reader Software that converts interface content to speech or braille, navigated largely by keyboard.
- Service design Designing the whole service including the parts the customer never sees, so the visible parts can work.
- Signifier The perceivable cue that tells a user an action is possible, as distinct from the possibility itself.
- Site map A diagram of a site's structure, and separately an XML file listing its pages for search engines.
- Sketching Drawing ideas quickly and roughly, to think through many options before committing to any.
- Skeuomorphism Interface design that imitates physical objects, using familiar appearance to signal function.
- Sprint A fixed, short period in which an Agile team completes an agreed set of work.
- Stakeholder Anyone with an interest in the outcome, which usually includes people who will never use the product.
- State diagram A map of every state something can be in and every permitted transition between them.
- Storyboard A sequence of drawings showing a person's experience over time, including everything around the screen.
- Style guide Documentation of how a brand or product should look and sound, without the working components.
T
- Technical debt The future cost of choosing a quick implementation now instead of a sound one.
- Think-aloud protocol Asking participants to verbalise their thoughts while working, so reasoning becomes observable.
- Touch target The area that responds to a tap, which needs to be larger than the icon inside it.
- Touchpoint Any point of contact between a person and an organisation, digital or not.
- Tree testing Testing whether people can find things in a proposed structure, with no visual design present.
- Typography The arrangement of type: face, size, spacing and hierarchy. On most screens it is the majority of the design.
U
- Usability How effectively, efficiently and satisfactorily specified users achieve specified goals in a specified context.
- Usability testing Watching representative users attempt real tasks, to find where a design fails before it ships.
- User experience A person's whole response to using a product, including before and after, of which usability is one part.
- User flow The path a person takes through a product to complete a goal, mapped step by step.
- User interface The surface through which a person operates a system: what they see, hear and manipulate.
- User journey map A visualisation of a person's experience over time across every touchpoint, including what they feel and where it breaks.
- User research Systematically learning about the people who will use a product, so decisions rest on evidence rather than assumption.
- User scenario A short narrative of a specific person achieving a specific goal in a specific situation.
- User story A short statement of a need in the form: as a role, I want something, so that some benefit.
- User-centred design An iterative process that grounds design in real users, tasks and environments, defined in ISO 9241-210.
V
W
- Waterfall A sequential process where each phase completes before the next begins, with design finished before build.
- WCAG The Web Content Accessibility Guidelines: the testable standard nearly every accessibility law refers to.
- White space The empty area around and between elements, which does the grouping and pacing work in a layout.
- Whiteboard challenge A design interview exercise: solve an unfamiliar problem live, thinking out loud, in 30 to 60 minutes.
- Wireframe A deliberately plain layout showing structure, hierarchy and content priority, with the visual design left out.
X
Z
Knowing the words is the easy part.
If you'd rather have someone apply them to your product, that's what I do.