Describe the preoperational stage (2-7 years old)

Preoperational derives from the idea of "operation" or mental activity. A child who identifies different animals as dogs, cats, and bears, for example, is performing a mental operation. Perception dominates children's thinking in this stage. Additionally many cognitive changes happen in children's such as enourmous progress in language development, growth in ability to use symbols, and learning a huge number of concepts. These concepts are concrete, however, and children in this stage have limited notions of abstract ideas such as fairness, democracy, and energy.