Mobile App Development Glossary: 60 Terms for Non-Technical Buyers

A native app is built separately for each operating system, using that platform's own language and tools: Swift or Objective-C for iOS, Kotlin or Java for Android. Each version is its own codebase, compiled for the device it runs on, which gives it the fastest available access to the camera, GPS, biometrics, and offline storage.

A hybrid app wraps standard web code, meaning HTML, CSS, and JavaScript, inside a native shell so it can be installed from an app store like any other app. The interface renders inside an embedded browser view rather than in native platform components.

Cross-platform development uses one shared codebase, written in a framework such as React Native or Flutter, that compiles into separate iOS and Android apps. The shared code carries most of the business logic and interface, while platform-specific behavior is written once for each side only where it is needed.

A progressive web app is a website built to behave like an installed app. It can be added to a home screen, work offline through cached data, and send push notifications on supported platforms, without going through an app store at all.

A web app is software that runs inside a browser and requires no installation, reached through a URL rather than an app store. Everything renders server-side or in the browser, and the user always needs a live connection.

iOS is Apple's operating system for iPhone and iPad, and it is a separate build target for every native or cross-platform app that includes Apple users. Publishing to it requires an Apple Developer Program membership and passing Apple's review before each release reaches users.

Android is Google's operating system, running on phones and tablets from many manufacturers across a wide range of screen sizes, chipsets, and OS versions. That variety is called fragmentation, and it is the main practical difference from iOS.

An APK is the installable package file for an Android app, equivalent to an installer file on a desktop computer. It contains the compiled code, assets, and manifest that Android needs to run the app.

A framework is a pre-built structure of code and tools that gives developers a starting foundation instead of writing every common piece from nothing. React Native, Flutter, Laravel, and .NET are all frameworks.

React Native is a cross-platform framework built and maintained by Meta that compiles one JavaScript codebase into native iOS and Android apps. It is one of the two dominant cross-platform choices, alongside Flutter.

Flutter is Google's cross-platform framework, written in a language called Dart, that compiles one codebase into native iOS and Android apps. It draws every interface element itself rather than mapping to platform components.

Backend development covers everything running on the server rather than on the user's device: the database, the business logic, authentication, integrations, and the APIs the app calls. A user never sees it directly and every meaningful action depends on it.

A wireframe is a low-detail layout sketch showing where elements sit on each screen and how screens connect, drawn before any color, typography, or imagery is applied. It exists to settle structure while structure is still cheap to change.

A mockup is a high-fidelity static image of a finished screen, showing real colors, typography, spacing, and content, with no working interaction. It is what the app will look like, frozen.

A prototype is a clickable, interactive model of the app used to test how people actually move through it, built before production code starts. Screens respond to taps and the flow can be walked end to end, with nothing behind it.

UI, or user interface, is the visual and interactive layer of an app: buttons, colors, typography, icons, spacing, and every element a user sees and touches. It covers what things look like and how they respond.

UX, or user experience, is the underlying logic of how someone moves through an app to complete a task, independent of how anything looks. It covers the sequence of steps, the decisions asked of the user, error handling, and what happens when something goes wrong.

A user flow is a diagram mapping every step someone takes to complete one specific task, from entry point to completion, including the branches where things go wrong. Checkout, onboarding, and password reset each have their own flow.

An MVP, or minimum viable product, is the smallest version of an app that delivers real value and can be put in front of actual customers. It ships with the features needed to prove the core idea works and deliberately excludes everything else until real usage shows what to build next.

A feature is one discrete, user-facing capability that can be scoped, estimated, and priced on its own, such as login, search, checkout, or push messaging. Features are the units a scope document is built from.

A roadmap is a prioritized, time-sequenced plan of which features ship now, which ship later, and roughly when. It communicates intent and sequence rather than contractual dates.

A design system is a reusable library of interface components, color and type rules, spacing standards, and usage guidance that keeps an app consistent as it grows. Every screen is assembled from the same tested parts.

Agile is a delivery method built on short, repeating cycles of building, testing, and adjusting, rather than one long fixed plan set at the start. Priorities are re-examined every cycle.

A sprint is one fixed work cycle inside an Agile project, typically one to four weeks, ending in a specific demonstrable piece of working software. Every sprint has an agreed goal set before it starts.

A backlog is the full, prioritized list of features, fixes, and technical work waiting to be built, ordered by what happens next. It is the single queue everything on the project passes through.

A standup is a short daily team check-in covering what was completed, what is next, and what is currently blocking progress. It runs in minutes rather than as a meeting.

Scope is the written, explicit list of what a project includes and, equally importantly, what it excludes. It is the document your price is calculated from and the reference point for deciding whether a later request is covered or is new billable work.

Scope creep is the gradual accumulation of features and requirements beyond the original agreement, approved informally in conversation rather than through a change order. No single addition looks significant, and the total moves the budget.

QA, or quality assurance, is the structured process of testing an app for defects, performance problems, security gaps, and usability failures before real users reach it. It covers functional testing, device testing, and the error states most builds forget.

Beta testing is the release of a near-finished app to a limited group of real users before public launch, to surface problems that internal testing does not reach. Real devices, real networks, real behavior.

TestFlight is Apple's official beta distribution platform for putting pre-release iOS builds in front of testers before an App Store submission. Builds still pass a lighter Apple review before reaching external testers.

Deployment is the process of moving a finished build into a live environment, whether that is an app store, a production server, or both. It covers build signing, environment configuration, database migration, and the rollback plan if something fails.

A release is one specific version of the app made available to users, whether that is the first public launch or a later update. Each release has its own build number, scope, and testing pass.

Post-launch support covers defect fixes, monitoring, platform compatibility updates, and small maintenance work after an app goes live. It keeps what you already paid for working, and does not include building anything new.

An API, or application programming interface, is the agreed set of rules that lets two separate pieces of software exchange data. Your app calls an API to take a payment, load a map, verify an identity, or reach your own backend server.

An SDK, or software development kit, is a packaged set of code, tools, and documentation that lets developers add one specific capability without building it from scratch. Payments, maps, analytics, crash reporting, push delivery, and identity verification are commonly added this way.

A tech stack is the full set of programming languages, frameworks, databases, and hosting services used to build and run an app. A complete stack names the mobile framework, the backend language, the database, and the cloud provider.

A database is the system that stores and structures an app's data so it can be searched, updated, and retrieved reliably and at speed. It holds your users, your transactions, and your content, and it is the asset that matters most if anything goes wrong.

The frontend is everything a user sees and interacts with directly: screens, buttons, navigation, animations, and layout. On a mobile app it is the code running on the device itself.

A push notification is a message delivered to a user's device from outside the app, appearing on the lock screen or notification tray whether or not the app is open. Delivery runs through Apple and Google's own notification services.

An integration is the work of connecting your app to a system you do not control, such as a CRM, a payment processor, an EHR, or an internal company database. Each connection has to handle authentication, data mapping between two different formats, error states when the other system is unavailable, and version changes announced with little warning.

A third-party service is any external tool or platform your app depends on that your team does not build, host, or control, from analytics and authentication to maps, messaging, and payments. Each one is a live dependency on another company's uptime and pricing.

Version control is the system that tracks every change made to an app's code, who made it, and when, so any previous state can be restored. Git is the current standard, hosted on services such as GitHub, GitLab, or Bitbucket.

Technical debt is the future cost created when a team takes a shortcut now to meet a deadline. The shortcut works, and it accrues interest: every later feature built on top of it takes longer, until the interest payment exceeds the cost of fixing the original decision.

Scalability is an app's ability to keep working correctly as its users, data volume, and transaction load grow, without needing a rebuild. It is decided by architecture choices made before the first feature is written, covering how data is stored, how capacity is added under load, and where the first bottleneck appears.

ASO, or app store optimization, is the practice of improving an app's title, keywords, description, screenshots, and ratings so it ranks higher in App Store and Play Store search. It is the app store equivalent of SEO, and store search is where most organic installs begin.

A statement of work is the formal document defining deliverables, timeline, cost, responsibilities, and acceptance conditions for a project. It is the document that actually governs the engagement, and the one a dispute is settled against.

A change order is a formal, signed amendment to the statement of work that adds, removes, or alters scope after the original agreement is in place. It restates the price and the timeline implications before the work begins.

Time and materials is a billing model where you pay for hours actually worked at an agreed rate, rather than one fixed number for a defined scope. Scope can change during the project without renegotiating the contract, because you are buying capacity rather than a specified deliverable.

A fixed bid is a single agreed price for a clearly defined scope of work, set before development begins. The vendor carries the risk of having underestimated, which is why a credible fixed bid usually follows a paid discovery phase that produced the scope behind it.

A milestone payment is a portion of the total fee released when a specific, agreed deliverable is completed and formally accepted. The milestone schedule sets how much of your money is committed at each stage of the build.

A discovery phase is an initial, separately priced stage where requirements, scope, technical approach, and risks are defined before a full quote is issued. Its output is a scope document detailed enough to price against.

Code ownership defines who legally holds the rights to the source code once the project is finished and paid for. It covers the application code, the configuration, and usually the designs and any custom framework built along the way.

IP assignment is the contract clause that formally transfers intellectual property, including source code, designs, and any custom components, from the vendor to you. It usually takes effect on final payment.

Source control access means you hold your own login to the repository, such as GitHub or GitLab, where your app's code lives, with visibility of the full commit history. Access from day one rather than at handover.

A retainer is a recurring fee paid for ongoing access to a vendor's team for support, small updates, or advisory work after launch. It reserves a set allocation of hours each month.

Staff augmentation means hiring individual developers from a vendor to work inside your own team, your process, and your management structure, rather than contracting the vendor to deliver a whole project. You direct the work; they supply the people.

A dedicated team is a vendor-assigned group working exclusively on your project for an agreed period, rather than shared across several clients at once. The same people stay with the product long enough to build context in it.

Acceptance criteria are the specific written conditions a deliverable must satisfy before you are contractually obliged to approve it and release payment. They are written before the work starts, not judged after it.

A warranty period is a defined window after launch, commonly 30 to 90 days, during which the vendor fixes defects in the delivered work at no additional charge. It covers work that did not meet the agreed specification.