An elevation is a view of a space seen from one side, a flat representation of one façade. Elevations allow you to see details of all your cabinetry and appliances.
A floorplan is the most fundamental architectural diagram, a view from above showing the arrangement of spaces in building in the same way as a map, but showing the arrangement at a particular level of a building.
My clients love the whole house floorplan. These are particularly useful if they plan on selling their property. Buyers are able to clearly see the representation of the entire space.