Résumé
X-ray absorption spectroscopy (XAS) has become a central tool for probing the local electronic and atomic structure of materials across physics, chemistry, and materials science, particularly under realistic operating conditions. The development of advanced synchrotron light sources, along with more affordable laboratory-based x-ray equipment, has made XAS increasingly accessible. Despite this progress, some hurdles remain for a newcomer to make use of this technique, namely the need for experimental considerations and the complexity of data curation, analysis and interpretation. This article provides a beginner-oriented introduction to XAS, with the aim of offering practical and conceptual guidance for first-time users. After introducing the fundamental principles of XAS, the distinction between x-ray absorption near-edge structure and extended x-ray absorption fine structure is outlined, and the information each regime provides on oxidation state, coordination environment, and local structure is discussed. Common experimental geometries and detection modes, including transmission, fluorescence, and electron yield, are reviewed with emphasis on their applicability and limitations. Typical data processing and analysis workflows are then summarised, with highlights on common pitfalls and best practices. Throughout, practical considerations relevant to experimental design and interpretation are emphasised, providing a foundation for readers seeking to apply XAS as an almost-routine characterisation tool.