Please look at this BBC Website link for a good, clear explanation.
This Swanton Abbott Performance link will take you directly to the official government page.
This Government Website link will let you check performance data from schools in England.
The Government will not publish Key Stage 2 school level data for the 2021-2022 academic year. They have archived data from 2018-2019 because they recognise that the data from that year may no longer reflect current performance.