The creation, understanding and control of mesoscopic chemical objects are at the core of many areas of chemistry and physics. Their preparation depends on a variety of nucleation and aggregation processes and they are exploitable for practical purposes, including fabrication techniques. At the opposite end, are cavitation phenomena. They also originate from a nucleation event, but result in the formation of a bubble. In recent years, bubbles have ceased to be a problem and have become increasingly more attractive for medical and industrial applications. Our understanding of bubble dynamics has steadily increased and we believe that it is timely to attempt to summarize in simple terms the knowledge accumulated in this area for a chemical audience. In this introduction, we focus on the nature of bubble formation, evolution and collapse. We discuss the macroscopic models that were developed at the beginning of the 20th century and accompany them with the results of more detailed molecular dynamics simulations.