The Early Years Foundation Stage is the standard used across the United Kingdom for children up to five. It sets out what young children should be learning, and — just as importantly — how they should be learning it.
In practice it means learning through play rather than worksheets, teachers who observe each child and adjust to them, and clear development milestones so nothing is left to chance. It is why our days look joyful and unstructured from the outside, and are carefully planned underneath.