General model of a computer

Every computer — from a smartwatch to a supercomputer — follows the same general model: Input, Processing, Output and Storage (the IPO+S model). Data goes in, the processor transforms it, information comes out, and both can be stored for later.

• Input: data enters the system (keyboard, mouse, touchscreen, sensors, microphone).
• Processing: the CPU carries out instructions on the data (calculations, comparisons, decisions).
• Output: the result is presented to the user (screen, printer, speaker).
• Storage: data and programs are kept for later use (SSD, hard drive, flash drive).
• Communication is often added as a fifth element — computers exchange data over networks.

• Data — raw, unprocessed facts (e.g. 72, 65, 80).
• Information — data that has been processed into something meaningful (e.g. "class average = 72%").
• CPU — the central processing unit, the "brain" that executes instructions.