A Directed Acyclic Graph (DAG) is a type of graph where each edge has a direction, and there are no cycles or loops, ensuring that you cannot return to a previously visited node. This structure is particularly useful in scenarios where tasks need to be executed in a specific order without circular dependencies. DAGs are commonly used in scheduling tasks, representing workflows, and in algorithms for data processing and optimization. For example, in workflow management systems and data pipelines, DAGs help model dependencies and execution order, ensuring that tasks are performed efficiently and in the correct sequence.