Cognitive development refers to the way children learn and process information. It includes improvement in attention, perception, language, thinking, memory, and reasoning.According to Piagets cognitive developmental theory, our thoughts and reasoning are part of adaptation. Cognitive development follows a definite sequence of stages. Piaget described four major stages of cognitive development.'Preoperational period' lasts around 2 to 6 or 7 years of age. In this stage, the child assumes that other people feel, see, and hear exactly the same as the child does.In this stage, the child faces problems with the irreversibility of thought, the concept of conservation, and struggles with the idea of centration. Due to the Centration in thought, the child can focus his attention only on one aspect of the situation at a time and cannot reverse the direction of his thought. For example,A 5-year-old is certain that rolling out a ball of clay into a snake creates more clay.A 6-year-old child reasons that a taller glass has more water than a shorter and wider container even though the liquid has been poured from the container to the glass in front of her eyes.Thus, it is concluded that Sara exhibits centration.Hint Animistic thinking/Animism makes the child imagine that toys are living beings and wants them to talk, walk, sit and stand, and to do as s/he says. For example, a child talking to a doll or feeding the doll.Seriation is the ability to order items along a particular dimension such as length or weight. For instance, arranging pencils from shortest to longest.