Learning objective
Explain data, databases, and apis, reproduce the worked example and justify a decision in the case study.
Before you begin
Websites and applications
Understand
A database stores structured facts; an API defines how systems exchange information.
Worked example
A quiz app can request five questions from an API and store the score separately.
Analysis and common mistakes
An API defines requests, responses and errors. The client must not decide access rights alone. Validate incoming data and prevent repeated requests from causing unintended duplicates.
Case study — reasoning
The network drops after submitting a quiz response. A unique attempt identifier supports retries without double-counting; the interface should distinguish saved from pending.
Knowledge check
Summary
A database stores structured facts; an API defines how systems exchange information.
Sources for further study and verification
AI-assisted draft · Educator review not completed · Unofficial supplementary resource