The article provides a comprehensive review of the discovery and properties of high-temperature superconductivity in layered iron-based compounds, particularly focusing on the FeAs-based materials. The authors highlight the rapid progress in understanding the mechanisms behind the superconductivity in these materials, which emerged in 2008 with the discovery of superconductivity at 26 K in LaFeAsO$_{1-x}$F$_x$. Subsequent studies revealed that other Fe-based superconductors could achieve even higher transition temperatures (up to 56 K) through doping or pressure application. The review covers various aspects of these materials, including their crystal structures, normal-state properties, and superconducting properties. Key topics include the relationship between structural distortions, magnetic ordering, and superconductivity, as well as the electronic and magnetic properties that are crucial for understanding the superconducting mechanism. The authors discuss the significance of the FeAs layers, the role of disorder and doping, and the comparison of Fe-based superconductors with layered cuprate superconductors. The article also addresses the challenges and open questions in the field, such as the nature of the superconducting order parameter, the mechanism of superconductivity, and the potential for technological applications. The review concludes with a summary of the current state of research and the remaining scientific issues to be resolved.The article provides a comprehensive review of the discovery and properties of high-temperature superconductivity in layered iron-based compounds, particularly focusing on the FeAs-based materials. The authors highlight the rapid progress in understanding the mechanisms behind the superconductivity in these materials, which emerged in 2008 with the discovery of superconductivity at 26 K in LaFeAsO$_{1-x}$F$_x$. Subsequent studies revealed that other Fe-based superconductors could achieve even higher transition temperatures (up to 56 K) through doping or pressure application. The review covers various aspects of these materials, including their crystal structures, normal-state properties, and superconducting properties. Key topics include the relationship between structural distortions, magnetic ordering, and superconductivity, as well as the electronic and magnetic properties that are crucial for understanding the superconducting mechanism. The authors discuss the significance of the FeAs layers, the role of disorder and doping, and the comparison of Fe-based superconductors with layered cuprate superconductors. The article also addresses the challenges and open questions in the field, such as the nature of the superconducting order parameter, the mechanism of superconductivity, and the potential for technological applications. The review concludes with a summary of the current state of research and the remaining scientific issues to be resolved.