An attachment, in its literal meaning, is a tie or fastening. Attachment, especially between people, is often defined positively as affection, devotion (Concise Oxford Dictionary) or even love, although harmful attachments, for example to a damaging substance or person, clearly exist.
An attachment as it is defined in attachment theory has a specific meaning, both in terms of its nature and the person to whom it applies. According to attachment theory, an attachment is a bond or tie between an individual and an attachment figure. In adult relationships, people may be mutual and reciprocal attachment figures, but in the relationship between the child and parent, this is not the case. The reason for this clear distinction is inherent in the theory. In attachment theory, an attachment is a tie based on the need for safety, security and protection. This need is paramount in infancy and childhood, when the developing individual is immature and vulnerable. Thus, infants instinctively attach to their carer(s). In this sense, attachment serves the specific biological function of promoting protection, survival and, ultimately, genetic replication.1 In the relationship between the child and the parent, the term 'attachment' applies to the infant or child and the term 'attachment figure' invariably refers to their primary carer. In the terms of attachment theory, it is incorrect to refer to a parent's attachment to their child or attachment between parents and children.
Attachment, therefore, is not synonymous with love or affection; it is not an overall descriptor of the relationship between the parent and child which includes other parent–child interactions such as feeding, stimulation, play or problem solving.
The attachment figure's equivalent tie to the child is termed the 'caregiving bond'.