Depending on the industry the names of these surveys are different but to a surveyor they generally mean a similar thing. In one sentence – Site surveys are where surveyors locate features & topography on a property producing digital data and/or a paper (PDF) survey plan usually with contours depicting levels to AHD (Australian Height Datum).
LPD Surveys typically calls these surveys feature/contour surveys.
One may need a feature/contour survey for building design, building and planning approvals through state & local governments, engineering or construction drawings, demolition plans, buildings additions or new dwellings and drainage or environmental studies.