2.1.4.1 : The Units of Data Measurement

Bit
A bit is represented by the numbers 1 and 0. They correspond to the states of on and off, true and false, or yes and no.
Byte
1 byte = 8 bit
Kilobyte (KB)
1 KB = 1024 bytes or 1 KB = 210 bytes
Megabyte (MB)
1 MB = 1 048 576 bytes or 1 MB = 220 bytes
Gigabyte (GB)
1 GB = 1 073 741 824 bytes 1 GB = 230 bytes
Terabyte (TB)
1 TB = 1 099 511 627 776 bytes or 1 TB = 240 bytes

Note:
1 KB = 1 024 byte
1 MB = 1 024 KB = 1 048 576 byte
1 GB = 1 024 MB = 1 048 576 KB = 1 073 741 824 byte
1 TB = 1 024 GB = 1 048 576 MB = 1 073 741 824 KB = 1 099 511 627 776 byte