Introduction: As children grow, they often acquire specific skills within predictable age ranges. These are often referred to as developmental milestones. Typical development is divided into five areas which are cognitive, communication, physical, self-help or adaptive, and social or emotional. In this task, we gave the option to choose between typical development, which is emotional or cognitive. So here, our group chose cognitive. We will discuss cognitive in typical development in more depth. As we know, cognitive development refers to the way they (children) think or it can be called thinking skills. Thinking skills refer to how they (children) learn, their understanding of something, how they solve their problems, how they memorize things, their attention and reasoning. It's all beneath their thinking capabilities. Developmental specialists usually observe how children apply learned concepts to everyday situations. Children develop their cognitive skills by learning about causes and effects in everyday activities and the similarities and differences in the things around them. We conclude that thinking skills help make all experiences more meaningful for children. So we chose the skill development of children aged 3 to 6 years. At these ages, children engage in imaginative play. They can also name some colors correctly. They can understand the concept of counting and know some numbers. They listen and can remember parts of a story. In addition to this, children of these ages can draw a face. They are better at understanding the concept of time. They can also name some letters... half of the paper... bal evidence as a memory strategy clearly increases with age. Although even young children can use rehearsal as a strategy if asked to do so, they typically fail to generalize the strategy to new tasks. Research suggests that this failure likely arises not so much from a lack of mediation or a lack of use but rather from a lack of production which may itself arise from an interaction between the costs and benefits of using a particular strategy. . As children become more skilled at using the strategy, the costs decrease and the benefits increase. Semantic organization is another strategy that improves with age as children use categorization and hierarchical relationships to process and store information. As with rehearsal, young children can come to use this strategy successfully if they are taught to do so using the Vygotskian sense. It can also help them.