A DataAdapter is a component in software development that acts as a bridge between a data source, like a database, and an application. It facilitates the retrieval, manipulation, and updating of data by providing methods to fill datasets and update the data source. This allows developers to work with data in a more structured way, often using DataSet objects to manage data in memory. Typically used in ADO.NET, a framework for data access in Microsoft applications, a DataAdapter supports various data operations, including selecting, inserting, updating, and deleting records. It simplifies the process of managing data connections and transactions, making it easier for developers to build data-driven applications.