This document provides an introduction and overview of augmented reality (AR) and the ARToolkit framework. It discusses key concepts of AR like combining real and virtual environments. It also explains how to use ARToolkit to develop basic AR applications, including how to incorporate custom markers and 3D models. The document guides users through creating a custom marker, adding it to ARToolkit, and displaying a 3D model over the marker in a sample application. Resources for further learning about AR and ARToolkit are also provided.