Attachment theory, developed by John Bowlby, is a psychological theory that explains the importance of the early relationship between a child and their caregiver in shaping their emotional development and social behaviors. The theory proposes that a secure attachment to a primary caregiver is essential for healthy emotional development and mental wellbeing throughout a person's life. Some key components of attachment theory include:

• The "attachment bond" - the strong emotional connection between a child and their caregiver.
• The "internal working model" - a child's expectations and assumptions about their relationships with others, based on their experiences with their caregivers.
• "Attachment styles" - the different ways that children develop attachments, including secure, insecure-avoidant, and insecure-ambivalent attachment styles.

Attachment theory has become a widely accepted framework in psychology and has influenced the way we think about early childhood development and parenting.