Welcome to Events and Responses! In the last series — Breaking Big Problems Down — you learned how decomposition turns a big, vague goal into a sequence of small, specific commands a computer can actually follow. Decomposition — breaking a big problem into smaller solvable pieces Each piece becomes a command — a clear, specific instruction Order matters — the sequence of commands must be correct Computers need complete, exact steps — they cannot infer or guess the missing parts That series answered: how do we turn a goal into instructions? But there is still something missing. When do those instructions actually run? Who or what starts them? Sometimes you start a programme by clicking a button. Sometimes the programme starts on its own when the clock hits a certain time. Sometimes a sensor detects something — heat, light, motion — and the programme begins. These starting triggers are called events . And understanding them is the key to building interactive things — apps, games, smart devices, websites. What You Learned Last Time Idea What It Means ------ -------------- Decomposition Breaking a big problem into small, solvable steps Commands Each small step becomes a specific, exact instruction Sequence Steps must happen in the right order Precision Instructions must be exact — not vague or guessable What You Will Learn in This Series Post The Big Idea ------ ------------- What is an Event? Something that happens — a tap, a timer, a sensor — that a programme can notice and respond to Events Are Everywhere Smoke alarms, automatic doors, phone notifications — events are all around you Events Inside Programs How programmes "listen" for events and run the right commands when they occur Putting It All Together A complete event chain — from trigger to decomposed response The Light That Knows When You Walk In Have you ever walked into a shop and the lights turned on automatically before you even touched a switch? There was no one watching for you. There was no button to press. Something detected your presence and triggered an action. That something was an event . The event — motion detected — caused the lights to turn on. This is what this series is about: how computers notice things happening in the world, and what they do in response. ✅ Start with the first post: What is an Event?