Net Terms Memory Measurements Most computer systems measure information in multiples of bytes. A byte is a unit of information that's used to represent a single character such as a letter, number, or other typographic symbol. The term that most computer users are familiar with is megabyte, which is equal to roughly one million bytes of information. The average 3 1/2 inch floppy disk, for instance, can hold just over 1.4 megabytes of data. As the amount of that can be stored grows larger, new terms have been created to measure information. Most hard drives currently have a storage capacity of at least one gigabyte (roughly equal to one billion bytes). In the future, you can expect to see storage devices that can hold up to a terabyte (one trillion bytes of information), or even a petabyte (one quadrillion bytes) worth of information.