Screed is a floor layer that can provide a suitable base for subsequent finishes. Its role and composition depend on the selected flooring system. It is not automatically the same layer as the load-carrying structural floor.
How this term relates to your project
Establish the existing substrate, proposed arrangement and connection to adjoining floor areas. Any underfloor heating and final covering need coordination with the complete build-up. Products impose requirements on preparation and readiness for later work. Agree which checks are made before the final finish is installed.
A number of elapsed days is not independent proof that the base is ready. Identify responsibility for levelling or local repairs if required. Quotations may treat screed, preparation and final covering as separate packages, so the boundaries should be explicit. Keep relevant product requirements with the floor specification for future maintenance and alterations.