The term disk space refers to the amount of data storage space available on a hard drive or other digital storage mechanism. The named derives from the use of disk-shaped platters in the storage area of hard disk drives in early computers, and has remained in common usage even for storage devices that are not shaped like disks.
Disk space is typically expressed in terms of bytes, like kilobytes, megabytes and gigabytes, with each unit representing 1024 of the previous unit of measure (i.e., 1024 kilobytes in a megabyte, 1024 megabytes in a gigabyte).
Simple web pages typically do not take up a significant amount of disk space, but media files such as images, audio and video can be disk space-intensive, especially in the case of high definition video files. The amount of disk space required for a website or application depends largely on the complexity of the site and the degree to which the site relies on local storage of media files. Some websites require less than a megabyte of disk space to support, while complex, dynamic, graphic and media-heavy sites can require gigabytes of storage space.