Hi Venu,
Like the others have pointed out, the keys that you see in VKOA represent the "conditions" that occur during a sale.
Whenever a sale is posted to accounting, SAP must find which account to post the revenues and discounts to.
For example, sales of a certain material can go to one revenue account, sales of other materials to a different account; or export sales can go to one account, local sales to another account.
Depending on all these conditions, (the material, type of sales etc) SAP can find a different account.
For example, we can classify the materials an enterprise sells as a product, service or equipment. In this case, we will define 3 account assignment groups for the material (Material.Grp) We can then define in the revenue account determination procedure, which GL account to post to in case we sell a service, which GL account to post to in case we sell a equipment and which GL account we post to in case we sell a product.
Similarly, we can classify customers as International Customers and Domestic Customers. We create 2 account assignment groups (international and domestic). Through revenue account determination, we can define which revenue account to post to in case of an international sale and which revenue account to post to in case of a domestic sale.
The "keys" are freely definable. We can define more key combinations than what is seen in VKOA to suit the needs of our business,