This document provides an overview of Business Process Model and Notation (BPMN) and how to use it at different levels of complexity. BPMN is a standard for modeling business processes visually that can be understood by both business and technical teams. It describes the elements of BPMN in four categories - workflow, organizing, readability, and special behavior. It then outlines the three levels of complexity in BPMN - basic, intermediate, and advanced - and provides examples to illustrate how to use different elements at each level. The goal is to help users get familiar with BPMN and understand how it can be used to both visually model and technically execute business processes.