Definitions

User: person who is using the device.
Owner: person who created the task to be fulfilled
Fulfill: adding file(s) to a task that satisfy some or all task requirements.
Private: a task that is not visible to any other user.
Public: a task that is visible to other users.
Task: an aggregation of item(s) requested by an Owner.
Item: a requirement consisting of file(s) of a single format with a name and description.
File: an audio, a picture, or a text document, or some other media.