Petri Nets were introduced and still successfully used to analyze and model discrete event systems especially in engineering and computer sciences such as in automatic control. Recently this discrete Petri Nets formalism was successfully extended to continuous and hybrid systems. This monograph presents a well written and clearly organized introduction in the standard methods of Petri Nets with the aim to reach an accurate understanding of continuous and hybrid Petri Nets, while preserving the consistency of basic concepts throughout the book. The book is a monograph as well as a didactic tool which is easy to understand due tomany simple solved examples and detailed figures. TOC:Bases of Petri Nets.- Properties of Petri Nets.- Non-Autonomous Petri Nets.- Autonomous Continuous and Hybrid Petri Nets.-Timed Continuous Petri Nets.- Timed Hybrid Petri Nets.- Hybrid Petri Nets with Speeds Depending on the C-Marking.