This chapter explains the issues that surround attachment theory. Attachment theory contemporarily comprises various schools of thought. Attachment theory is a map of relating in everyday life and caring relationships of all kinds. This chapter provides an overview of attachment in the context of child and adult development for understanding how the patterns begun in childhood continue into adult circumstances, where they might be limiting or inappropriate for a variety of reasons. Attachment is one part of human development, so below sections sketch the background of child development. The purpose of the chapter is to prepare the ground for the definitions of the patterns and processes of the following chapter. Below, there is a deepening of attention to the detail of how consciousness defends itself against the consequences of suboptimal care provision and creates its own solutions to psychological meanings of distress. It contributes to keeping clients in mind, in empathising, and understanding the pushes and pulls in any relationship between two or more people. According to the different roles of care-givers and receivers involved, there are specifically different sorts of provision and receipt. Through understanding the secure base phenomenon of the secure process, the key aspects for understanding attachment theory are explained.