The government has issued information leaflets and videos for parents about the end of key stage assessments (often referred to as SATs) for year 2 and year 6 pupils.
Please click on the following like https://www.gov.uk/government/publications/key-stage-1-and-2-national-curriculum-tests-information-for-parents

Please also see the following leeter & leaflet:

Letter to parents Y6 SATs_2018.pdf

Information brochure KS2 tests_2018.pdf