Secure attachment has to do with your child knowing that you are trustworthy, knowing that you are there, that you will respond to his/her needs. Secure attachment is vital. Attachment in early childhood, secure or insecure, has been found to have an impact in future relationships. In other words, if, as a young child, you were securely attached to your caregiver, later on, adult relationships will be easier for you.
Attachment is something I am very passionate about. Some day I would love to have the time to write a long post on attachment. In the meantime, here is this article: