Quarterly reports refer to a set of financial statements that are published by public companies on a quarterly basis. These reports provide an overview of the company's performance, including its revenue, expenses, and profitability, during a specific time period - usually three months. Quarterly reports are important tools for investors who use them to make informed decisions about buying or selling stock in a particular company. They also provide valuable insights into the overall health of an industry and can help analysts identify trends and patterns that may impact future business operations.