Unified Modeling Language (UML) is a way of visualizing a software program using a collection of diagrams. That is one of the simplest ways to define it.
In equally simple terms, it is a modeling language used to analyze, design and implement software-based systems.
However, UML diagrams can be applied to more than just software engineering and development.
There are over a dozen types of UML diagrams that are used for a range of different purposes and have significant variances in complexity.
One of the simplest types, which also happens to be the most suitable diagram for modeling business processes, is called the activity diagram.
This is the diagram we will be focusing most of our attention on in this post, though we will take a quick look at some of the other common types for the sake of context and because you may also find them useful beyond the purpose of process modeling & optimization.