Creepage and clearance are additional parameters that one should be aware of. Creepage is the distance between the input and the output, typically along the length of the package. It is also the shortest distance between the two conductive leads, across the isolation barrier, measured along the surface. Clearance, on the other hand, is the shortest distance between two conductive points across the isolation barrier, measured through air. In the example shown on this slide, it uses a straight line; however, in most circumstances, it is actually the shortest distance and could be curved. As a result, typically, in most cases clearance is shorter than creepage. Also shown on the slide is a table listing typical package specifications for creepage and clearance.