Dwarf galaxies are the least massive, most abundant and most widely distributed type of galaxy. Hence, they are key to testing theories of galaxy and Universe evolution. Dwarf galaxies sufficiently close to have their gas and stellar components studied in detail are of particular interest, because their properties and evolution can be inferred with accuracy. This Review summarizes what is known of the stellar and chemical properties of star-forming dwarf galaxies closer than ~20 Mpc. Given their low metallicity, high gas content and ongoing star formation, these objects are supposed to resemble the first galaxies that formed at the earliest epochs, and may thus represent a window on the distant, early Universe. We describe the major results obtained in the past decade on the star formation histories, chemical abundances, galaxy formation and evolution of star-forming dwarfs, and the uncertainties still affecting these results.

矮星系是质量最小、数量最多、分布最广的星系类型。因此，它们是检验星系和宇宙演化理论的关键。矮星系足够接近，可以对其气体和恒星成分进行详细研究，这是特别令人感兴趣的，因为可以准确地推断出它们的性质和演化。这篇评论总结了已知的恒星形成矮星系的恒星和化学特性，这些星系的距离小于约 20 Mpc。鉴于它们的低金属丰度、高气体含量和持续的恒星形成，这些天体应该类似于在最早时期形成的第一个星系，因此可能代表了遥远的早期宇宙的窗口。我们描述了过去十年在恒星形成历史、化学丰度、