Memory Details

1 bit (binary digit*) = the value of 0 or 1

8 bits = 1 byte

1024 bytes = 1 kilobyte

1024 kilobytes = 1 megabyte

1024 megabytes = 1 gigabyte

1024 gigabytes = 1 terabyte

1024 terabytes = 1 petabyte

Abbreviations

1 kilobyte = 1 k

1 megabyte = 1 MB

1 gigabyte = 1 GB

1 terabyte = 1 TB

1 petabyte = 1 PB

Size in "bytes"

Kilobyte (KB) = 1,024

Megabyte (MB) = 1,048,576

Gigabyte (GB) = 1,073,741,824

Terabyte (TB) = 1,099,511,627,776

Petabyte (PB) = 1,125,899,906,842,624

EXPLANATIONS and NOTES The Decimal System is a base 10 number system that uses ten digits (0,1,2,3,4,5,6,7,8,9). 1000 is attained as follows: 1 x10 = 10 x 10 = 100 x 10 = 1000 (kilo) The Binary System is a base 2 number system that uses only two (bi) numbers or digits (0 and 1) to represent all values. The unit closest to 1000 is attained as follows: 1 byte x 2 = 2 x 2 = 4 x 2 = 8 x 2 = 16 x 2 = 32 x 2 = 64 x 2 = 128 x 2 = 256 x 2 = 512 x 2 = 1,024 bytes (1 kilobyte) A "2 gig hard drive" means the drive holds "2 gigabytes" (2,147,483,648 bytes). Just one CD can hold 650 MB, so 2 GB could be filled with about 3 CD's. Terabyte databases are becoming common, and rumor has it that there are probably a few petabyte databases in the United States Pentagon.