Any Soil Mechanics/Foundation Enginering text will tell you. So will I.
Definitions: UCS - Unconfined Compressive strength. Done in a lab. Indicates shear strength of soil. Correlates with angle of internal friction.
SPT - Standard Penetration Test. Field Test. Measures the number of blows it takes a standard weight to push a standardised split barrel sampler a fixed distance into the ground. Normally correlated with allowable bearing pressure for foundation design.
CPT - Cone Penetrometer test. Also a field test. Measures the resistance achieved while pushing a standard cone into the ground at a fixed rate. Also used to estimate bearing capacity and settlements.
You need to read Bowles or other Foundation design text to understand the applicability and limitations of the tests and their correlations.
