Under Info at the bottom of the window you will see information regarding the last order date and last order number, last invoice date and last invoice number for this customer.
You will also see the customer's payment history in number of days. This represents the average value of all the payments received. The payment history is used to calculate an incoming payments forecast. This is an information field that cannot be modified. You can also see a modification log for the customer.
You can also see who created the customer and when, as well as who modified the customer and when, if any changes have been made.