The task to begin obtaining an understanding of the business using a data-first approach falls under the "Risk Assessment" phase. In this phase, auditors typically use various tools and methods, such as the GL Analyzer, to analyze the data and gain insights that inform their risk assessments. This process helps identify potential risks and areas of concern within the financial statements. By starting with an analysis of the entity's records, often involving a data-first approach with tools like the GL Analyzer, auditors can efficiently assess the client's transactions and better understand the business before proceeding with the overall risk assessment.