Overview
Also known as 'Build Verification Testing,' smoke testing is a subset of test cases that cover the most important functionality of a component or system. If the smoke tests fail, the build is considered 'broken' and further testing is halted.
Origin
The term comes from hardware testing, where a device is plugged in and checked to see if it literally starts smoking.
Purpose
To provide fast feedback on the basic stability of a build, saving time by not running more extensive tests on a fundamentally flawed version.