Microsoft Azure Data Lake Storage Rest API allows users to perform various operations on their Data Lake storage accounts programmatically. Some of the key functionalities it provides include creating, managing, and monitoring data lakes, uploading and downloading files, managing file and folder permissions, and executing bulk operations. The API enables developers to integrate Data Lake storage capabilities into their applications, automate data processing workflows, and access and manipulate data stored in Azure Data Lake Storage in a secure and efficient manner. Overall, the Rest API simplifies the management and manipulation of large volumes of data within Azure Data Lake Storage.