This handbook introduces speckle techniques to nonspecialists to help them understand the basic principles of speckle interferometry. The book mainly focuses on the use of speckle patterns with direct phase-measuring methods that produce an instantaneous phase. The major electronic speckle pattern interferometry (ESPI) techniques are presented using simplified mathematical notation that includes rigid-body and standard-body displacements to estimate object pose changes with six degrees of freedom. Additionally, the adoption of temporal phase unwrapping instead of spatial phase unwrapping is promoted. This handbook also includes a summary of recent industrial applications, with an update on current research in the ESPI field.