An Abstract Syntax Tree (AST) is a tree representation of the abstract syntactic structure of source code. Each node in the tree represents a construct occurring in the code, such as expressions, statements, or declarations. The AST abstracts away certain syntax details, focusing instead on the hierarchical relationships between different elements of the code. ASTs are commonly used in programming language compilers and interpreters, such as those for Python, Java, or C++. They facilitate various tasks, including code analysis, optimization, and transformation, by providing a structured way to understand and manipulate the underlying code logic.