Topography is a detailed graphical representation of the surface shapes and features of the Earth, illustrated by contour lines.  A topographic / existing conditions survey is a survey of both the elevation and physical aspects or properties of a parcel of land.  Typically, this information is used for land planning or as a base map for other design work such as an OWTS design or a Proposed Conditions Site Plan and are often required by Architects, Civil Engineers and Landscape Architects.  Features commonly shown on a topographic / existing conditions survey plan include contour lines, buildings, above ground and evidence of below ground utilities, roadways, trees, edges of vegetation and other improvements.