IEC 61131-3 is an international standard that defines programming languages for industrial automation systems. It is part of the IEC 61131 series, which focuses on programmable controllers. The standard specifies five programming languages: Ladder Diagram, Function Block Diagram, Structured Text, Instruction List, and Sequential Function Chart, allowing flexibility in how automation tasks are programmed. This standard aims to improve interoperability and ease of use in programming industrial control systems. By providing a common framework, IEC 61131-3 helps engineers and developers create, maintain, and share code more efficiently, ultimately enhancing productivity in automation projects.