Final answer:
A financial statement or financial report is the key source of historical financial data used for generating comparative financial reports, allowing stakeholders to assess and analyze a company's financial health and performance over time.
Step-by-step explanation:
The file that primarily provides historical financial data for comparative financial reports is often known as a financial statement or a financial report.
These reports are essential for a variety of stakeholders including investors, creditors, and internal management to assess a company's financial health over time.
Historical financial data contained in these reports typically include the balance sheet, income statement, and cash flow statement, among others, and provide vital information for financial analysis and decision-making processes.
This historical data is key for conducting ratio analysis, trend analysis, and comparing a company's financial performance across different reporting periods.
A financial statement or financial report is the key source of historical financial data used for generating comparative financial reports, allowing stakeholders to assess and analyze a company's financial health and performance over time.