Bit

A bit (a contraction of binary digit) is a unit of data that consists of a (0 or 1, also represented on/off and true/false). Groups of 8-bits of data are measured as bytes.

Variations

 * A binary kilobit (KiB) consists of 1,024 bits ( 210 )
 * A binary megabit (MiB) consists of 1,024 kilobits, or 1,048,576 bits ( 220 )
 * A binary gigabit (GiB) consists of 1,024 megabits, or 1,073,741,824 bits ( 230 )
 * A binary terabit (TiB) consists of 1,024 gigabits, or 1,099,511,627,776 bits ( 240 )
 * A binary petabit (PiB) consists of 1,024 terabits, or 1,125,899,906,842,624 bits ( 250 )
 * A binary exabit (EiB) consists of 1,024 petabits, or 1,152,921,504,606,846,976 bits ( 260 )

Starting with iOS 11 and Mac OS X 10.6, Apple stopped using binary values and switched to decimals, causing a "megabyte" to report 1,000,000 bytes instead of 1,048,576 bytes, as had been done in the past. This created an illusion of a slight increase in data capacity (memory and storage).


 * A decimal kilobit (kB) consists of 1,000 bits ( 103 )
 * A decimal megabit (MB) consists of 1,000 kilo bits, or 1,000,000 bits ( 106 )
 * A decimal gigabit (GB) consists of 1,000 mega bits, or 1,000,000,000 bits ( 109 )
 * A decimal terabit (TB) consists of 1,000 giga bits, or 1,000,000,000,000 bits ( 1012 )
 * A decimal petabit (PB) consists of 1,000 tera bits, or 1,000,000,000,000,000 bits ( 1015 )
 * A decimal exabit (EB) consists of 1,000 peta bits, or 1,000,000,000,000,000,000 bits ( 1018 )