So why does it cause confusion? Several reasons. Most sizes are referred to in Mega or Giga bytes so many people have been accustomed to this. For example in magazines or advertisements selling electronic equipment (tablet’s, digital cameras, etc.) and computers running Windows they’re referred to as this, but that’s where the confusion comes in, and a bit of a rant because of it.
The difference between 1GiB and 1GB is marginal, but when you increase this to several tens or thousands, it throws the scale way off. Not only that, Windows runs in base 2, but actually displays it using the prefix for base 10.
Gibibyte (GiB) is one of the standard units used in the field of data processing and data transmission (along with mebibyte (MiB), kibibyte (KiB), etc.). Gibibyte, mebibyte, and kibibyte are defined as powers of 2. 1 GiB equals 2 bytes or 1,073,741,824 bytes. Gibibyte is closely related to gigabyte (GB), which can be a synonym of gibibyte or can refer to 10 bytes or 1,000,000,000 bytes in accordance with International System of Units (SI).
Gigabyte (GB) can have different meanings in different contexts. When referring to computer memory, gigabyte is allways a “power of two” – 1,073,741,824 bytes, but when measuring hard drive capacity it is often defined as 1,000,000,000 bytes. Generally, operating systems calculate disk and file sizes using binary numbers, so a new 500 GB drive you’ve just purchased would be reported by the OS as “465.66 GB” (meaning 465.66 GiB).