A SEF is a snapshot of your school at a point in time
It identifies your school's strengths and weaknesses and (often) grades the school against the current Ofsted inspection framework or another basis for grading. In completing the self-evaluation form (SEF), your senior leadership team can determine which areas of improvement to focus on.
There's no set format that your school has to use to present the SEF. However, Ofsted will request to see 'a summary of any self-evaluation and/or improvement plan or equivalent' from your school on the first morning of an inspection (see paragraph 106 of the School Inspection Handbook).
What's in the SEF
For example, many schools organise the SEF around the education inspection framework (EIF). If that's the case in your school, your headteacher will evaluate your school against the grade descriptors for each