Cell motility and migration play important roles in both normal biology and in disease. On one hand, migration allows cells to generate complex tissues and organs during development, but on the other hand, the same mechanisms are used by tumor cells to move and spread in a process known as cancer metastasis. One of the primary cellular machineries that make cell movement possible is an intracellular network of myosin and actin molecules, together known as "actomyosin", which creates a contractile force to pull a cell in different directions.In this video, JoVE presents a historical overview of the field of cell migration, noting how early work on muscle contraction led to the discovery of the actomyosin apparatus. We then explore some of the questions researchers are still asking about cell motility, and review techniques used to study different aspects of this phenomenon. Finally, we look at how researchers are currently studying cell migration, for example, to better understand metastasis.