Earth here means composition of the surface of the earth , the soil and other minerals present in the soil. The upper part of the surface is called soil ,Stone, sand, iron, lime etc., all these are parts of soil. All these physical elements are available in limited quantity and on a particular place. This depends on the composition of surface, its form and size, trees and vegetation grown upon it etc. that whether it will be appropriate to inhabit at such a place or not . Moreover if there is a residence there , what type of construction should be there. Availability of essential building materials and their transportation also depend upon the formation of soil . Soil can be categorized on the basis of its shape , touch , taste and sound . We must take care that it suits our physique while selecting land for building and collecting building material.