This chapter provides an overview of metaverse technology. The aim of this opening chapter is twofold. Primarily, it seeks to set out an overview of the technology: what is the metaverse? Three overlapping aspects are vital to understanding these technologies’ implications: the structure, the user experience and the enabling technologies. This chapter will explore each in turn. The second aim is to set out a brief history of the interaction between sexual offences and virtual reality. Although we have seen a growth in literature in the private law sphere, particularly concerning data protection and intellectual property rights, accounts of the impact on criminal law primarily rely on individuals who have come forward about their experiences.