Quick meaning
A built-in digital SIM that lets you switch mobile providers without inserting a physical card.
Think of it like this
Like having a digital key card that can be updated instead of a physical door key.
Where you may see this
You may hear this when buying a device, asking for repairs, or checking phone and computer settings.
Why it matters
Understanding the hardware term helps you choose the right device and explain problems more clearly when asking for help.
Say it simply
eSIM means: A built-in digital SIM that lets you switch mobile providers without inserting a physical card.