The accounts receivable (AR) is a key part of a company's financial management system, and its main function is to keep track of the money owed to the company by its customers or clients. Here are some of the key functions of accounts receivable:

1. Recording sales transactions: AR records all sales made on credit, including the invoice date, amount, and payment terms.
2. Monitoring payment due dates: AR keeps track of the payment due dates for each invoice, and sends reminders to customers if payments are overdue.
3. Collecting payments: AR is responsible for collecting payments from customers, either through direct communication with the customer or by using a collection agency.
4. Resolving payment disputes: If there is a dispute over payment, AR investigates and resolves the issue in a timely manner.
5. Maintaining accurate records: AR ensures that all payment records are accurate and up-to-date, and reconciles any discrepancies between the company's records and the customer's records.
6. Providing financial information: AR provides financial information to management and other stakeholders, such as the company's cash flow, revenue, and accounts receivable turnover ratio.

Overall, accounts receivable plays a critical role in ensuring that a company receives the revenue it is owed and maintains a healthy cash flow.