Scaling by 1,000
In the decimal system, each unit is 1,000 times the previous one: 1 KB = 1,000 bytes, 1 MB = 1,000 KB, 1 GB = 1,000 MB, 1 TB = 1,000 GB. Storage manufacturers use this system, which is why a drive is sold as '500 GB'.
The Binary Alternative
Computers often work in powers of two, so operating systems use binary units where each step is 1,024×: 1 KiB = 1,024 bytes, 1 MiB = 1,024 KiB, etc. Because 1,024 > 1,000, a 500 GB drive shows only about 465 GiB in your OS — the same bytes, different counting.
Scale at a Glance
| Unit (decimal) | Bytes | Typical file |
|---|---|---|
| 1 KB | 1,000 | short text |
| 1 MB | 1,000,000 | song or photo |
| 1 GB | 1,000,000,000 | a movie |
| 1 TB | 1,000,000,000,000 | a hard drive |