Regression, Smoke & Sanity Testing

Difference between Regression, Smoke & Sanity Testing

Regression	Smoke	Sanity
Testing all areas related to the new feature deeply.	Testing all (wide) areas related to a new feature, NOT deeply. It determines if we should do further testing.	It is same as Regression Testing but here you make a risk judgment call and compromise part of your testing.
	When we receive a build, a smoke test is run to verify if the build is stable and can it be considered for further testing? It is mainly done to test the stability of a build.	It focuses on one or few areas of functionality. It is used to determine a small section of the application is still working after a minor change.
		When a new build is received with small revisions, instead of doing a from end to end regression, sanity is performed so as to find out if the build has indeed fixed the issues and no further issue has been introduced by the fixes.