Overview:

An operational version of a system or part of a system that demonstrates a subset of the capabilities to be provided in the final product.

Purpose:

Deliver incremental value to the user and customer, and provide a testable artifact for verification.

Main Description:

This working version of the system is the result of putting the implementation of the system through a build process (typically an automated build script) that creates an executable version of the system, or one that runs. This executable version of the system will typically have a number of supporting files that are also considered part of this composite artifact.

 
Key Consideration:

In an iterative lifecycle, each build must evolve from the previous iteration's build, adding more functionality and improving quality.

The purpose of early builds that minimize or eliminate a risk or verify architectural decisions is to achieve consistently stable builds in later iterations.