IEC 61131 is an international standard that defines programming languages and software architecture for industrial automation and control systems. It provides guidelines for developing programmable logic controllers (PLCs) and ensures compatibility and interoperability among different devices and systems. The standard includes five programming languages: Ladder Diagram, Function Block Diagram, Structured Text, Instruction List, and Sequential Function Chart. By standardizing these languages, IEC 61131 helps engineers and developers create efficient and reliable control systems, facilitating easier maintenance and integration across various platforms.