Preschool helps children:

• Get new knowledge and skills – for example, they start learning more about numbers, letters and words
• Improve their communication and social skills through playing and interacting with other children and adults
• Make new friends and develop new relationships with adults
• Develop physical skills – for example, children learn to balance on play equipment and practise fine motor skills like drawing with a pencil and cutting with scissors
• Develop problem-solving and creative thinking skills
• Develop responsibility, independence, confidence and self-worth through doing things like looking after their own belongings and spending time away from home
• Get ready for the transition to primary school.

article from https://raisingchildren.net.au/