Before cloud storage and USB sticks, people used a small, square piece of plastic called a floppy disk to save their work. A floppy disk could store 1.44 megabytes—barely enough to hold a single photo from a modern smartphone! That’s smaller than most music files, and thousands of times smaller than a typical video.
Back then, every bit of space mattered. If your file was too large—even by just a few kilobytes—it wouldn’t fit. You had to understand exactly how big your file was, and that meant knowing the difference between bits and bytes, kilobits and kilobytes, and even kibibits and mebibytes.
Today, we have more storage than ever, but understanding file size is still essential—whether you're uploading videos, sending images, or building a program that needs to run efficiently.
A photo of Floppy Disk
Everything you see on a screen—whether it’s a photo, a message, or a video—comes down to the bit.
The word bit stands for binary digit. It is the smallest unit of data in computing and can only have two possible values:
0 or 1
🔌 Off or On
❌ False or True
Just like a light switch can only be on or off, a bit can only be 0 or 1.
Think of it as a tiny yes/no decision.
"Is the pixel on?" → 1
"Is the pixel off?" → 0
Bits are everywhere. Computers don’t "see" pictures or words the way we do. They only understand patterns of 0s and 1s. When you combine lots of bits, you can start building: