/glossary

name: glossary
description: "Use this skill when the user doesn't understand a technical term, asks 'what is a [technical concept],' 'what does [term] mean,' seems confused by jargon in another skill, or is encountering developer concepts for the first time. Covers the 50+ technical terms non-technical founders encounter most, explained in plain English with no jargon."

Technical Glossary

Plain-English definitions for every technical term you'll encounter while building your SaaS. No jargon. No condescension.

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The Basics

**API (Application Programming Interface)** A way for two pieces of software to talk to each other. When your app gets weather data from a weather service, it's using an API. When you connect Stripe for payments, you're using Stripe's API. Think of it as a menu at a restaurant — it tells you what you can order (request) and what you'll get back (response).

**Database** Where your app stores information. Users, their data, settings — everything lives in a database. Think of it as a collection of spreadsheets that your app can read and write to. The most common type for SaaS is PostgreSQL (often shortened to "Postgres").

**Frontend** The part of your app that users see and interact with — buttons, pages, forms, menus. Built with HTML, CSS, and JavaScript. When someone says "React app" or "Next.js app," they're talking about frontend frameworks.

**Backend** The part of your app that users don't see — the logic, data processing, and database connections that happen on a server. When a user clicks "Save," the frontend sends the data to the backend, which stores it in the database.

**Server** A computer that runs your app and responds to requests from users. When someone visits your website, their browser sends a request to your server, which sends back the page. Modern hosting (Vercel, Railway, etc.) manages servers for you — you don't need to set one up.

**Framework** A pre-built structure for building software, so you don't start from scratch. Like using a house kit instead of cutting every board yourself. Common ones: React (frontend), Next.js (full app), Django (Python backend), Express (Node.js backend).

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Building & Deploying

**Repository (Repo)** A folder for your project's code, tracked by Git (version control). Think of it as a Google Doc with infinite undo and version history. Usually hosted on GitHub.

**Git** A system that tracks every change to your code. If you break something, you can go back to any previous version. GitHub is a website that hosts your Git repositories.

**Deploy / Deployment** The process of putting your app on the internet so anyone can use it. "Deploying to Vercel" means uploading your code to Vercel's servers so it's live at a URL.

**Environment Variables** Secret settings (API keys, passwords, database connections) stored outside your code. Like a locked file cabinet that your app can open at runtime. You set these in your hosting provider's dashboard — never put them in your code.

**Build** The process of converting your source code into the optimized version that runs in production. When you "build" a Next.js app, it compiles everything into fast, minified files ready to serve to users.

**CI/CD (Continuous Integration / Continuous Deployment)** Automatic building and deploying. When you push code to GitHub, CI/CD automatically tests it and deploys it. Most modern hosting (Vercel, Netlify) does this for you.

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Web & Networking

**DNS (Domain Name System)** The internet's phone book. Translates "yourapp.com" into the IP address of the server that runs your app. When you "configure DNS," you're telling the internet where your domain points.

**SSL / HTTPS** Encryption between the user's browser and your server. The padlock icon in the browser. All modern hosting provides this automatically. If your site shows "Not Secure," SSL isn't set up yet.

**Domain** Your website's address (yourapp.com). You buy one from a registrar (Namecheap, Cloudflare) for ~$10/year and point it at your hosting.

**URL** The full address of a specific page: `https://yourapp.com/dashboard`. The domain is part of the URL.

**CORS (Cross-Origin Resource Sharing)** A security rule that controls which websites can talk to your API. If your frontend is at `app.com` and your API is at `api.app.com`, you need to configure CORS to allow them to communicate. When something "works locally but not in production," CORS is often the culprit.

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Database Terms

**Schema** The structure of your database — what tables exist, what columns each table has, and how tables relate to each other. Designing your schema means deciding how to organize your data.

**Migration** A versioned change to your database structure. Adding a new column, creating a new table, or changing a field type. Like git for your database — each change is tracked and can be applied in order.

**Query** A request to read or write data in the database. "Get all users who signed up this week" is a query. Written in SQL (Structured Query Language).

**Row Level Security (RLS)** A database feature that restricts which rows each user can see. Essential for SaaS: User A should never see User B's data. The database itself enforces this, not just your app code.

**Foreign Key** A link between tables. If a "projects" table has a `user_id` column that points to the "users" table, that's a foreign key. It says "this project belongs to this user."

**Index** A lookup optimization for your database. Like an index in a textbook — instead of scanning every row, the database can jump directly to the rows it needs. Add indexes to columns you search or filter by frequently.

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Authentication & Security

**Authentication (Auth)** Verifying who a user is. Login, signup, password reset — that's authentication. "Are you who you say you are?"

**Authorization** Determining what a user is allowed to do. After logging in, can they edit this document? Can they access admin settings?