Mass Grading means the movement of earth by mechanical means to alter the gross topographic features (elevations, slopes, etc.) to prepare a site for final grading and the construction of facilities
Grading in civil engineering and landscape architectural construction is the work of ensuring a level base, or one with a specified slope, for a construction work such as a foundation, the base course for a road or a railway, or landscape and garden improvements, or surface drainage.
Land grading is a leveling of the surface. Dirt from higher up is moved into the lower lying areas to create a nice level surface to serve as the foundation for your project. Sometimes land grading may require you to move in additional dirt from somewhere else to complete the job.