# Physical SIM
> A physical SIM is the small removable card that identifies your phone number to a mobile network.
Topics: Connectivity, Smartphones
Difficulty: Everyday
Aliases: SIM card, nano SIM
Updated: 2026-06-26T08:00:00.000Z
## In one analogy

It is like a tiny ID badge your phone shows the network.

## Go deeper
A physical SIM is the small removable card that identifies your phone number to a mobile network. In everyday buying decisions, the useful question is not just what the spec says, but what it changes for comfort, cost, speed, safety, or battery life.