X-ray spectra unravel the composition and properties of materials by analyzing the characteristic X-rays emitted when electrons undergo transitions between atomic energy levels. These spectra provide insights into the atomic and electronic structure, chemical environment, and elemental composition of various substances. X-ray diffraction, absorption, photoelectron, and fluorescence spectroscopies are powerful techniques that utilize X-ray spectra for material characterization, elemental analysis, medical imaging, and industrial applications.