Bytes, kilobytes, megabytes, and gigabytes
The byte is a unit of digital data, comprising of a string of 8 bits. One byte constitutes roughly the same amount of data as one character, such as a letter, numeral, punctuation mark, space, or line-feed command.
Today’s computers work with files which are very large in terms of bytes. Thus, kilobytes (units of 210=1024 bytes), megabytes (units of 220 =1,048,576 bytes), and gigabytes (units of 230 =1,073,741,824 bytes) are mentioned by people talking about computers. The abbreviations for these units are KB, MB, and GB, respectively. Alternatively you may see them abbreviated as K, M, and G.
As computer technology advances during new century, you will be hearing more about a unit of data called as terabyte. This is equivalent to 240 bytes, or 1,048,576 MB. And the day may come when we use the terms petabyte (PB or P) commonly, which refers to 250 bytes or 1,048,576 GB, and even exabyte (EB or E), which refers to 260 bytes of 1,048,576 TB. Think about the fact that even a computer with the storage or memory capacities in the exabyte range cannot begin to approach sophistication and subtlety of human mind. But nevertheless, a machine juggling a few exabytes of data may have a fascinating, if perhaps alien, kind of intelligence.
Personal computer memory is commonly specified in megabytes or gigabytes. The same holds true for the removable data storage media like diskettes. The hard drive in a computer has capacity measured in gigabytes, although a few get into terabyte range. Older computers may have hard drive capacities quoted as a few hundred megabytes or less than that.