Toddlerhood is a time of great change for children; among other things, children are self aware, language is developing and motor skills are improving by leaps and bounds. This is a period of exploration and growth and parents serve as a secure base in this process.
Look around at any playground and you will see toddlers moving about in all directions and engaging in various play activities using all of their newly developing skills. What you will also see is the toddler keeping a close eye on the parent and going back to check in every once in awhile. Securely attached children feel safe and free to roam and explore when they know their parent is watching and is nearby.
Children also look to their parent to understand emotions. When a child accomplishes something new and feels excited about it, he/she looks to or verbally engages the parent for a reaction. When the parent claps and smiles and praises the child, the child comes to recognize his/her emotions and feels encouraged to explore and experience more.
Providing a secure base for children to explore is a key element for their overall physical, cognitive, psychological, and social development.