Step 1: Use the telescope/microscope analogy:
Microeconomics is like a microscope — it zooms into one consumer or one firm's decision-making in isolation. Macroeconomics is like a telescope — it looks at the big picture, the economy as a single interconnected system.
Step 2: Contrast their central questions:
Micro asks "why does this consumer buy more tea when its price falls?" Macro asks "why does the whole economy's price level rise (inflation) or why does total output fall (recession)?"
Step 3: Contrast their tools:
Micro relies on individual demand and supply curves for a good; Macro relies on aggregate demand (AD) and aggregate supply (AS) curves for the entire economy, and on national-income accounting (GDP, GNP).
Final Answer:
Both study economic behaviour, but at fundamentally different levels — the individual unit (micro) versus the economy-wide aggregate (macro).