The book presents the various seismic imaging methods currently in use in the Oil and Gas industry in a unified and almost equation-free approach. Guided step by step through each method well illustrated by figures and examples, the reader will discover differences between time and depth imaging, how they impact the quality of the seismic image, the distinction between Kirchhoff, Gaussian Beam and other Beam techniques, principles of ray-based tomography and how it may be used after wave-equation methods, in what sense two-way Reverse Time Migration differs from one-way Shot Point migration, what are the emerging routes for migration velocity analysis, what can we expect from Full Waveform Inversion and at what cost, how 3D and wide azimuth acquisition impact imaging, and answers to many other questions.