Front-end, Back-end, and Database — The Structure of an App

Front-end is what users see and interact with — browsers, mobile UI, desktop windows. Back-end is the server logic: authentication, business rules, integrations. The database stores durable state.

Most real products need all three, plus hosting and operational concerns. When someone says “I need an app,” clarifying which layers exist — and who owns each — is the first step to a sane plan and a fair price.