The Introduction sets out the central themes that arise in the chapters that follow. These themes form a common thread throughout the later chapters, providing a consistent structure for the arguments that are presented. The Introduction also provides an explanation of the terminology that is used throughout the work to describe various family forms. Parenting is multifaceted, and so this work does not attempt to address all aspects. Instead, the focus is on common pathways to parentage that are available to same-sex couples, and the analysis focuses on applying the best interests principle in each context. The final section of Introduction provides an overview of the chapter structure, which demonstrates the parameters of the research.