Hi, welcome to the site. If you read 'about' and the introduction information in the front of the EYFS document you'll find the details to help express the purpose in your own words.
EYFS 2014 on Gov.uk
Ultimately the existence of EYFS is to ensure there's a minimum standard of learning, development and care for children aged 0-5 attending registered settings in England. This enables settings to comply with all the laws that underpin an individual's rights, equality & safeguarding and provides a framework for Ofsted to inspect against.
If you have a handbook you'll find supportive reading for this -
Level 3 EYE learner book on amazon.co.uk
Best wishes