Architects typically use four distinct terms to break down the design phase of a project. These are:
Conceptual design: loose, possibly freehand, sketches of a design approach
Design development: selecting materials, integrating systems and describing details
Schematic design: more precise sketches of a preferred design
Construction drawings: the drawings that completely describe what’s needed to build
Keep in mind that everything up to construction drawings is preliminary design, while the construction drawings represent the final design.