What purpose do notes to financial statements serve?

The correct answer highlights that notes to financial statements provide additional details and insights that are not included in the main financial reports. These notes serve a critical purpose in enhancing the clarity and transparency of the financial statements, helping users such as investors, creditors, and analysts understand the company's financial position more comprehensively.

The notes can include information about accounting policies, potential liabilities, risks, and other factors that can affect the company’s performance. This additional context is crucial for users needing to make informed decisions based on the financial reports, ensuring they do not misinterpret or overlook important information.

Other options, while they touch on aspects of financial reporting, do not capture the essence of the notes to financial statements as effectively. Summarizing financial performance is typically done through key metrics reported in income statements, while simple explanations of calculations or future projections are usually found in different contexts or sections of financial reporting. Thus, the main role of notes is to enhance the understanding of the overall financial statements by providing crucial explanatory details.