This lecture delves into the concept of X-ray imaging in synchrotron science, discussing the various techniques used to visualize structures at different scales, from atomic to macro. The instructor explains how X-ray imaging methods cover a wide range of characteristic lengths and how they are essential for understanding the structural complexity of materials. The lecture also explores the classification of techniques as imaging or non-imaging, emphasizing the importance of X-ray computed tomography and other related methods in the imaging domain.