Glossary · Plain English
Forty terms that founders meet when planning and building an app, each explained in a sentence or two.
Last updated: October 2026. Written by Athar Ahmad, Certified Bubble.io Developer and Tech Architect, Simple Automation Solutions.
Quick answer
This glossary explains 40 common app development terms in plain English, including MVP, PRD, scope, user flow, database, API, integration, no-code, SaaS, multi-tenancy, privacy rules and workload units. Use it to follow developer conversations, read quotes and ask better questions.
Key takeaways
- Scope, PRD and MVP define what you are paying for.
- Data types and privacy rules determine soundness and security.
- Every integration adds work and cost.
- A staging or test version protects your live app from changes.
- Scalability and workload units affect performance and running costs.
Talking to developers can feel like listening to another language. This glossary explains 40 terms founders meet when planning and building an app, in plain English, so you can follow conversations, read quotes and ask better questions.
What do these 40 terms mean?
| Term | Plain-English meaning |
|---|---|
| MVP (Minimum Viable Product) | The smallest version of a product that delivers real value to early users and lets you learn before investing more. |
| PRD (Product Requirements Document) | A written description of what a product should do, who uses it, what is in the first release and how it behaves. |
| Discovery | The planning phase before building, in which scope, users, data and costs are worked out. |
| Scope | The agreed list of what will and will not be built. |
| Scope creep | The gradual growth of a project beyond what was agreed, usually through small unplanned additions. |
| User flow | The step-by-step path a user takes to complete a task, such as signing up or submitting a request. |
| User story | A short description of a need, usually written as “As a [user], I can [do something] so that [benefit].” |
| Wireframe | A simple sketch of a screen’s layout, without final design. |
| Front end | The part of an app users see and interact with. |
| Back end | The behind-the-scenes part that stores data and runs logic. |
| Database | Where an app stores its information, organised so it can be searched and linked. |
| Data type | A category of information the app stores, such as Client or Invoice, with its own fields. |
| Field | A single piece of information within a data type, such as a client’s email address. |
| Workflow | A set of automatic actions triggered by an event, such as sending an email when a form is submitted. |
| Backend workflow | A workflow that runs on the server, often on a schedule or in the background, rather than in the user’s browser. |
| API (Application Programming Interface) | A way for two software systems to exchange information, such as an app talking to a payment provider. |
| Integration | A connection between your app and another service. |
| Webhook | A message one system sends to another automatically when something happens. |
| No-code | Building software through visual tools instead of writing code. |
| Low-code | Building software with visual tools plus some hand-written code. |
| Vibe coding | Creating software by describing what you want to an AI tool and letting it generate the code. |
| SaaS (Software as a Service) | Software that customers use online, usually for a recurring subscription. |
| Multi-tenancy | A design where many customers share one application but each sees only their own data. |
| Authentication | Proving who a user is, usually with a login. |
| Authorization | Deciding what an authenticated user is allowed to see and do. |
| Role-based access | Giving different permissions to different types of users, such as client, staff and admin. |
| Privacy rules | In Bubble.io, rules that control which users can see which data. |
| Encryption | Scrambling data so only authorised parties can read it. |
| Two-factor authentication (2FA) | Requiring a second proof of identity, such as a code, in addition to a password. |
| Responsive design | A layout that adapts to different screen sizes, such as phones and desktops. |
| Progressive web app (PWA) | A web app that can be added to a phone’s home screen and feel more like an installed app. |
| Native app | An app built for a specific operating system and distributed through an app store. |
| Staging or test version | A separate copy of an app used to test changes before they go live. |
| Deployment | Releasing a new version of an app to users. |
| Scalability | An app’s ability to handle growth in users and data without slowing down or failing. |
| Workload units | Bubble.io’s usage-based measure of the work an app does, which affects hosting cost. |
| Technical debt | Shortcuts taken during building that make later changes slower and costlier. |
| Sprint | A short, fixed period of focused work, often one to two weeks. |
| GDPR | The European Union’s data protection regulation, with a UK equivalent, governing how personal data is handled. |
| Uptime | The proportion of time an app is available and working. |
Which terms matter most when hiring a developer?
- Scope, PRD and MVP: they determine what you are paying for.
- Data type and privacy rules: they determine whether the app is sound and secure.
- Integration and API: each one adds work and cost.
- Staging or test version: protects you from changes breaking the live app.
- Scalability and workload units: shape performance and running cost.
For more, read how to choose a development partner, what to cut before you build and our security guide.
Frequently asked questions
What is the difference between no-code and low-code?
No-code builds software entirely with visual tools. Low-code uses visual tools but also allows or requires some hand-written code.
What is the difference between a PRD and a wireframe?
A wireframe sketches how screens look. A PRD describes behaviour, users, rules and data. Many projects need both, and the PRD comes first.
What is an MVP?
A minimum viable product is the smallest version of a product that delivers real value and lets you learn from users.
What does multi-tenancy mean?
It means many customers use one application while each sees only their own data, which is how most SaaS products work.
What are workload units?
Workload units are Bubble.io’s measure of the work an app performs, which influences the platform’s usage charges.
Got a term you want explained, or an idea to discuss?
Email us your question or your project. We will answer in plain English.
Athar Ahmad, Certified Bubble.io Developer and Tech Architect, Simple Automation Solutions
About Simple Automation Solutions (SA Solutions)
Simple Automation Solutions is a Bubble.io development studio led by Athar Ahmad, a Certified Bubble.io Developer and Tech Architect. It builds web and mobile apps, client portals and SaaS products for founder-led businesses such as law firms, accounting firms, boutique agencies and consultants. Services include a free 30-minute Idea Audit, a $345 Discovery Sprint (a Product Requirements Document delivered within 24 hours, credited toward the build) and builds starting at $3,500. Website: sasolutionspk.com.
