The Sun provides a critical benchmark for the general study of stellar structure and evolution. Also, knowledge about the internal properties of the Sun is important for the understanding of solar atmospheric phenomena, including the solar magnetic cycle. Here I provide a brief overview of the theory of stellar structure and evolution, including the physical processes and parameters that are involved. This is followed by a discussion of solar evolution, extending from the birth to the latest stages. As a background for the interpretation of observations related to the solar interior I provide a rather extensive analysis of the sensitivity of solar models to the assumptions underlying their calculation. I then discuss the detailed information about the solar interior that has become available through helioseismic investigations and the detection of solar neutrinos, with further constraints provided by the observed abundances of the lightest elements. Revisions in the determination of the solar surface abundances have led to increased discrepancies, discussed in some detail, between the observational inferences and solar models. I finally briefly address the relation of the Sun to other similar stars and the prospects for asteroseismic investigations of stellar structure and evolution.

太阳为恒星结构和演化的一般研究提供了重要的基准。此外，有关太阳内部特性的知识对于理解太阳大气现象（包括太阳磁循环）也很重要。在这里，我简要概述了恒星结构和演化的理论，包括所涉及的物理过程和参数。接下来是对太阳演化的讨论，从诞生到最后阶段。作为解释与太阳内部相关的观测的背景，我对太阳模型对其计算所依据的假设的敏感性进行了相当广泛的分析。然后，我讨论通过日震研究和太阳中微子检测获得的有关太阳内部的详细信息，并通过观测到的最轻元素的丰度提供进一步的限制。太阳表面丰度测定的修订导致观测推论和太阳模型之间的差异增加，对此进行了一些详细讨论。最后，我简要阐述了太阳与其他类似恒星的关系以及恒星结构和演化的星震研究的前景。