The chapter reviews the current understanding of the chemical composition of the Sun, primarily derived from the analysis of the solar photospheric spectrum. It highlights the agreement between solar and meteoritic abundances, which are used to construct a Standard Abundance Distribution (SAD). The historical introduction traces the development of solar abundance studies from H.N. Russell's pioneering work in the 1920s to more recent advancements. Key techniques and sources of solar abundances, including spectroscopy, particle collection, and helioseismic data, are discussed. The chapter also addresses the observed variations in the chemical composition of the Sun, such as element migration and fractionation, particularly in the outer layers of the Sun. The solar photosphere is noted as the layer with the most comprehensive data available.The chapter reviews the current understanding of the chemical composition of the Sun, primarily derived from the analysis of the solar photospheric spectrum. It highlights the agreement between solar and meteoritic abundances, which are used to construct a Standard Abundance Distribution (SAD). The historical introduction traces the development of solar abundance studies from H.N. Russell's pioneering work in the 1920s to more recent advancements. Key techniques and sources of solar abundances, including spectroscopy, particle collection, and helioseismic data, are discussed. The chapter also addresses the observed variations in the chemical composition of the Sun, such as element migration and fractionation, particularly in the outer layers of the Sun. The solar photosphere is noted as the layer with the most comprehensive data available.