Megabytes (MB) and gigabytes (MB) refer to units of measurement indicating how much data a digital storage device can hold, where one gigabyte equals 1,024 megabytes. A megabyte is approximately one million bytes, whereas a gigabyte is about one billion bytes. Megabytes and gigabytes are the most common units of measurement when specifying memory sizes in computers and other electronics.
An even smaller unit of measurement than the MB is a kilobyte (KB), which is 1,024 bytes. The largest unit is a terabyte (TB), which is made up of 1,024 GB. For comparison, 1 byte can store one letter of the alphabet, whereas 1 MB can store a medium-sized novel.