Cognitive development is characterised by the way a child acquires knowledge, learns, and interacts with their surroundings. Playing is one of the main ways a child explores the world, they learn to experiment, think and solve problems through play. Try reading books and reciting poems along with your toddler, constant repetition will increase their ability to retain information. Give your toddler basic puzzles, different coloured blocks, wooden pegs etc to stimulate their brain. Take trips to museums, parks and farmer's markets to provide them with hands-on experience.