Different File Sizes (Bytes, KB, MB, GB, TB, etc..)

A byte is a sequence of 8 bits (enough to represent one alphanumeric character) processed as a single unit of information. A single letter or character would use one byte of memory (8 bits), two characters would use two bytes (16 bits).

Put another way, a bit is either an 'on' or an 'off' which is processed by a computer processor, we represent 'on' as '1' and 'off' as '0'. 8 bits are known as a byte, and it is bytes which are used to pass our information in its basic form - characters.

An alphanumeric character (e.g. a letter or number such as 'A', 'B' or '7') is stored as 1 byte. For example, to store the letter 'R' uses 1 byte, which is stored by the computer as 8 bits, '01010010'.

A document containing 100 characters would use 100 bytes (800 bits) - assuming the file didn't have any overhead (additional data about the file which forms part of the file). Note, many non-alphanumeric characters such as symbols and foreign language characters use multiple bytes.

A kilobyte (KB) is 1024 bytes, a megabyte (MB) is 1024 kilobytes and so on as these following demonstrate.

1 Bit = Binary digit

8 Bits = 1 Byte

1024 Bytes = 1 Kilobyte

1024 Kilobytes = 1 Megabyte

1024 Megabytes = 1 Gigabyte

1024 Gigabytes = 1 Terabyte

1024 Terabytes = 1 Petabyte

1024 Petabytes = 1 Exabyte

1024 Exabytes = 1 Zettabyte

1024 Zettabytes = 1 Yottabyte

1024 Yottabytes = 1 Brontobyte

1024 Brontobytes = 1 Geopbyte

There are lots of different "types" of disks out there. You've probably already heard of most of them -- floppy disks, CDs, DVDs, and of course the hard disk that lives inside every computer. Hard disks come in many different sizes. Usually in the range of 20GB to 120GB. Table 4 lists the storage capacities of common types of disks. The column on the right describes the capacity in relation to the capacity of a floppy disk, just to give you some perspective on how greatly these capacities vary.

Floppy Disk = 1.4 MB

CD = 700 MB

DVD = 4.7 GB

Hard disk = 20 GB to 120 GB

According to International Data Corporation, the total amount of global data is expected to grow to 2.7 zettabytes during 2012. This is 48% up from 2011.