Hi, welcome to silkysteps, this depends which home nation you work in. If in England it's how your setting uses the information found in the EYFS framework
- the ELG's, possibly the 2 yr progress check and at the end of a child's EYFS the profile outcomes. The development matters guidance might be used and maybe the five positive outcomes as documented in Every child matters.
A level 3 handbook
will support research in greater depth, if you can ask a colleague/senior management in your setting or placement they'll be able to help explain the ways things are done xx