A neighbor brings a phone to the bay. A message on the screen says the storage is full. "It will not take one more photo!" she says. Rocket scrolls through hundreds.
Raven looks at the little bar on the settings page. "What do you notice about how much of the shelf is used?"
Nova glows a gentle green. "Would you like a hint? A shelf only has so much room. Something old has to move before something new fits."
Storage keeps information without power. It can do this in two main ways.
A hard drive has a spinning metal disk. A tiny arm writes and reads with magnets. Magnets stay put when the power is off.
A solid state drive has no moving parts. It uses special chips that trap a tiny charge. The charge stays trapped with the power off.
Memory cards and the storage in phones and tablets use the same kind of chips.
| Kind of storage | How it keeps files | Moving parts? |
|---|---|---|
| Hard drive | Magnets on a spinning disk | Yes, it spins |
| Solid state drive | Charge trapped in chips | No |
| Memory card | Charge trapped in chips | No |
Storage has a size. When it is full, nothing new can be saved.
The phone in the bay had hundreds of photos and many apps. The shelf was packed.
A kid may look at the storage bar with a grown-up. A kid never deletes files they did not make.
A grown-up can move old photos to another place, like a backup drive.
| Statement | True or false? |
|---|---|
| A hard drive keeps files with magnets. | ? |
| A solid state drive has a spinning disk. | ? |
| Storage needs power to keep files. | ? |
| A kid may delete any file to make room. | ? |
Well done! You know how the shelf keeps files, and what to do when it is full. Tomorrow you will measure how big files are.