The ratio of the difference between the void ratio of the soil in its loosest state and its natural void ratio (e) to the difference between the void ratios in the loosest and fully dense state, is generally termed as

Soil mechanics is the theory of mechanical properties of soils. Foundation engineering - the theory of stability of foundations and construction methods used for their production. This also includes predicting the deformation of the substrate.

The objectives of soil mechanics are (1) to study the physical and mechanical properties of soil, (2) to apply this knowledge for the solution of practical engineering problems, and (3) to replace by scientific methods the empirical ones of design used in foundation and soil engineering in the past.