The document discusses non-conventional machining processes. It begins with an introduction explaining the limitations of traditional machining methods and the need for alternative processes. It then classifies non-conventional machining into four main categories: mechanical, thermal, chemical, and electrochemical machining. Specific examples of processes are described within each category, such as ultrasonic machining, electric discharge machining, and electrochemical machining. The document provides details on the mechanisms and applications of several important non-conventional machining methods.