This document provides an overview of augmentative and alternative communication (AAC). It defines AAC as any form of communication that enhances or supplements speech and writing. It discusses the four main functions of communication and describes various AAC options including unaided systems like gestures and aided low-tech systems like communication boards. High-tech AAC systems with speech output and touch screens are presented. Considerations for choosing between dedicated AAC devices and iPad apps are outlined. Factors to consider in AAC assessment and implementation are provided like language skills, environments, and training support. Core and extended vocabulary are discussed.