With the same logic that lets us call 1024 bytes a kilobyte, we can also refer to 1024 kilobytes as a 'megabyte'. (The Greek word megas means great.) Megabyte is abbreviated MB. The Greek word gigas means giant, so 1024 megabytes are called a gigabyte, which is abbreviated GB. Similarly, a terabyte (teras means monster) equals 1,099,511,627,776 bytes. Terabyte is abbreviated TB.