ELI5: How do computers store information?

Imagine your computer is like a giant light switch board with millions of tiny, tiny light switches. Each switch can be either ON or OFF.

• ON means the switch is flipped up and a tiny bit of electricity is flowing.
• OFF means the switch is flipped down and no electricity is flowing.

We use bits to represent these ON and OFF states.

• ON is represented by the number 1.
• OFF is represented by the number 0.

Now, let's say we want to store the number 5. We need more than one switch! Computers group these switches together into groups of eight. Eight bits make a byte.

Here's how a computer might store the number 5 using eight switches (a byte):

00000101

Each place in the group of eight represents a different power of two (1, 2, 4, 8, 16, 32, 64, 128). To get the number 5, we turn ON the switch representing '4' and the switch representing '1'. That's 4 + 1 = 5!

Computers use lots and lots of these groups of switches (bytes) to store everything. A hard drive or SSD is just a place where these switches are physically located and can be flipped ON and OFF very quickly. The more switches (more storage space), the more information a computer can store.