The general properties of smart toys are examined in this chapter, along with new studies on the subject. Smart toys are modern toys with both physical and technological elements that enable two-way interactions between children and smart toys to do useful activities. The characteristics of smart toys as cognitive tools to facilitate learning are analyzed in this chapter, along with projects based on them. In order to comprehend the potential consequences of smart toys on children, this chapter also discusses the relationship between smart toys and children’s developmental phases, with a focus on motivation.