The storage used by your application records contribute to the most important part of the overall data storage allocation on the platform. There is also another type of storage used by the files uploaded or created on the platform. From the Storage Usage page under the Setup menu, you can see a summary of the records used, including those that reside in the Salesforce Standard Objects.
Tip
The preceding page also shows which users are using the most amount of storage. In addition to the individual's User details page, you can also locate the Used Data Space and Used File Space fields; next to these are the links to view the users' data and file storage usage.
The limit shown for each is based on a calculation between the minimum allocated data storage depending on the type of organization or the number of users multiplied by a certain amount of MB, which also depends on the organization type; whichever is greater becomes the limit. For full details...