According to the top Google result, The Unified Software Development Process or Unified Process is an iterative and incremental software development process framework. [excerpt from Wikipedia].

What is that you might ask? It’s a way of working. The most well known is RUP or Rational Unified Process, developed by the company Rational in 1996.

It has 3 main pillars:

• Iterative development
• Use case driven
• Architecture centric.

The whole framework is designed to make planning for software development faster.

It provides a template to divide the work into 4 phases, which are inception, elaboration, construction and transition.

Inception is the first step, where everything beings. From budget assignment, feature lists, use cases, schedules and responsibilities.

Elaboration refers to more detailed information or you could say, project specifics. Features, requirements, technologies to be used, how basically.

Construction is self explanatory. This is where code actually is made, every feature will be implemented during the development sprint.

Transition is where the software gets delivered to the customer initially or revisions that can include bug fixes or additional features.

Here’s a detailed explanation:

Sources:

http://wiki.c2.com/?UnifiedSoftwareDevelopmentProcess

https://en.wikipedia.org/wiki/Rational_Unified_Process