1 mile is 1.609 KM.
now imagine the abbreviation for a mile is KM. it would be confusing.
megabytes and mebibytes have the same abbreviation, but they are different measurements of the same thing.
megabytes is like miles, only a few places still use it but it is still used
mebibytes is like KM its used by almost everyone but windows and the standards committee JEDEC.
drive makers sell a 1 Terabyte drive knowing that windows will show a 931 Gibibytes, inches vs cm.