Hard drives are the most common method of storing digital data, used with all types of computers. They offer greater storage capacity than any other commercially available storage medium.
Hard Drive Storage Capacities
As of 2010, hard drives are available with storage capacities up to 2 terabytes (TB), with 3.5TB hard drives on the horizon.
Hard drive manufacturers round off their numbers in stating the capacity of their hard drives. For instance, 1 gigabyte actually equals 1,073,741,824 bytes, but hard drive manufacturers round the number down. Similarly, a hard drive labeled as a 250 gigabytes (GB) drive actually holds only 232.88GB.
Determining Free Space
On a Windows PC, you can determine how much space you have available on your hard drive by clicking on the "Computer" or "My Computer" icon, depending on which version of Windows software you are running. On a Mac, you can find your available hard drive capacity by clicking on the hard drive icon and then on "Get Info."