Concept: Work Product
A Work Product is something meaningful resulting from a process: Roles use Work Products to perform Tasks and produce Work Products in the course of performing Tasks.
Main Description

Work Product

A Work Product is a general abstraction that represents something resulting from the process.  Work Products include:

Tasks have input and output Work Products. Roles use Work Products to perform Tasks, and produce other Work Products in the course of performing Tasks. Work Products are the responsibility of a single Role, making responsibility easy to identify and understand, and promoting the idea that every piece of information produced in the process requires the appropriate set of skills. Even though one Role may "own" the Work Product, other Roles will use the Work Product, perhaps even updating it if the Role has been given permission to do so.

Major Artifacts and information flow in the Rational Unified Process

Popular Work Products in Software Development, and the approximate dependency relationships between them.

Note that "Work Product " is the term used to describe what other processes denote using terms such as Artifact, work unit, and so on. In UMA, Deliverables are only considered to be the subset of all Work Products that will end up being delivered into the hands of the customers and users, usually as part of a formal or contractually agreed hand-over.