Quick meaning
A portable battery that stores charge to recharge your phone or other devices when you are away from a power socket.
Think of it like this
Like a spare fuel canister for your phone.
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
Power Bank means: A portable battery that stores charge to recharge your phone or other devices when you are away from a power socket.