Testing the basic or critical features of an application before doing thorough testing or rigorous testing is called as smoke testing.

It is also called Build Verification Testing  because we check whether the build is broken or not.

Whenever a new build comes in, we always start with smoke testing, because for every new build – there might be some changes which might have broken a major feature ( fixing the bug or adding a new feature could have affected a major portion of the original software).

In smoke testing, we do only positive testing – i.e., we enter only valid data and not invalid data.