Websites that do something: logins, databases, SaaS, MVPs, and real-time features.

A website mainly shows information: pages you read, like a brochure, blog, or portfolio. A web app is software you use in the browser: it takes input, does something with it, and saves state, like Gmail, a bank dashboard, or a booking system. The line is interactivity and data, not looks.

SaaS (software as a service) is software you access online and pay for by subscription, instead of buying and installing it. You use it in a browser, the provider runs and updates it, and you pay monthly or yearly. Slack, Shopify, and Notion are SaaS. Most business software now works this way.

An MVP (minimum viable product) is the smallest version of an app that delivers real value and can be put in front of users. You start with one because it gets you to real feedback fastest and cheapest, before you spend heavily building features nobody has confirmed they want.

Authentication is how an app confirms who a user is, usually a login with an email and password, a social login, or a one-time code. It's paired with authorization, which decides what that verified user is allowed to do. Together they protect accounts and control access to data.

A progressive web app (PWA) is a website that behaves like an installed app: users can add it to their home screen, it can work offline, and it can send notifications, all without going through an app store. It's built with normal web technology, so one build works across devices.

Web apps store data in a database on the server, not in the page. When you save something, the app sends it to the backend, which writes it to the database and can retrieve it later for you or others. Small preferences may also be kept in your browser, but the real record lives on the server.

Real-time features update instantly without a page refresh: live chat, notifications, collaborative editing, and live dashboards. Instead of the browser repeatedly asking the server for updates, the server pushes changes the moment they happen, so everyone sees the same thing at once.

Build a web app if you want one product that runs everywhere in the browser, cheaper and faster to ship, with no app store. Build a native app if you need the best performance, deep device features (camera, sensors), offline power, or the credibility and reach of being in the app stores.

An admin dashboard is the private, logged-in part of an app where a business manages everything: customers, orders, content, settings, and reports. Users never see it. It's the control room where your team runs the operation, often the most valuable part of a custom build even though it's invisible to the public.

A focused MVP typically takes a few weeks to a few months. A full-featured product takes several months to over a year. The timeline tracks scope: the number of features, integrations, user roles, and the level of polish and testing. There's no fixed answer because there's no fixed size.

An integration is a connection between your app and another system so they share data or trigger actions automatically. Connecting a store to a payment provider, a site to an email tool, or an app to a CRM are all integrations. They let separate tools work as one and remove manual copying between them.

Apps handle growth by adding capacity and removing bottlenecks: running more servers, caching frequent results, optimizing the database, and using a CDN to serve content from locations near users. Modern cloud platforms can add capacity automatically as traffic rises, which is called scaling.

Roles and permissions control what each user can see and do. An admin might manage everything, a staff member might handle orders, and a customer might only see their own account. Roles group permissions so you can assign a whole set of abilities at once instead of one by one.

You need a web app when users must log in, save data, or get personalized results, or when you want to automate a workflow your team runs manually. If you mainly need to present information and generate enquiries, a website is enough and far cheaper. Start from what users must do.