What are Smoke Testing and Sanity Testing?

Smoke Testing:

Smoke testing originated in the hardware testing practice of turning on a new piece of hardware for the first time and considering it a success if it does not catch fire and smoke. In software industry, smoke testing is a shallow and wide approach whereby all areas of the application without getting into too deep, is tested. Smoke testing is normal health check up to a build of an application before taking it to testing in depth.

Sanity Testing:

A sanity test is a narrow regression test that focuses on one or a few areas of functionality. Sanity testing is usually narrow and deep. Sanity testing is to verify whether requirements are met or not, checking all features breadth-first.