Accounts Receivable (AR)
Money owed to a company by a customer who purchased goods or services on credit
Simply put accounts receivable is the money owed by customers to a business but has not been paid yet, normally represented by a series of invoices.
Accounts receivable or just "receivables" represents credit extended by a supplier to its customers and normally have fixed terms that require payment to be made within a defined time period, ranging from a few days to a few months.
In the mobile business, AR is payments to the app publisher due from the app stores (Google and Apple), mobile ad networks, affiliate networks, etc. The delay in payment for these accounts receivables can be as long as 60 days from when you first earned the revenue to actually receiving the funds.