Step 1: Define the computer network types by their geographical range.
PAN (Personal Area Network): Spans a very short distance, typically a few meters, to connect devices for a single person (e.g., connecting a mouse, keyboard, or headset via Bluetooth).
LAN (Local Area Network): Covers a limited area like a single building or a campus.
MAN (Metropolitan Area Network): Spans a city or a large town.
WAN (Wide Area Network): Covers a large geographical area, such as a country or the entire globe.
Step 2: Compare their sizes.
Based on the definitions, the hierarchy of size from smallest to largest is PAN& Lt;LAN& Lt;MAN& Lt;WAN. Therefore, the Personal Area Network is the smallest.