The Rational Unified Process is a software development approach similar to the agile approach.

It revolves around the principle of each iteration involving all four phases, however the later phases being given more attention the further the project develops

Phases

Phase One - Inception

The beginning of the project. Stakeholders are identified, as well as the required resources, architecture, architecture and costs involved

Phase Two - Elaboration

Problem domain established. Detail analysis of requirements

Phase Three - Construction

Things get made.

Phase Four - Transition

Release to production