An invoice or bill is a commercial document issued by a seller to the buyer, indicating the products, quantities, and agreed prices for products or services the seller has provided the buyer. An invoice indicates the buyer must pay the seller, according to the payment terms. wikipedia.org

Bookkeeping is the recording of financial transactions. Transactions include sales, purchases, income, receipts and payments by an individual or organization. Bookkeeping is usually performed by a bookkeeper. wikipedia.org

Accounts payable is a file or account sub-ledger that records amounts that a person or company owes to suppliers, but has not paid yet (a form of debt), sometimes referred as trade payables. wikipedia.org

Accounts receivable also known as Debtors, is money owed to a business by its clients (customers) and shown on its Balance Sheet as an asset. wikipedia.org

SAP HANA, short for "High-Performance Analytic Appliance" is an in-memory, column-oriented, relational database management system developed and marketed by SAP AG. wikipedia.org

SAP Business One is an integrated enterprise resource planning (ERP) solution for small and medium-sized businesses, as well as divisions and subsidiaries of larger companies.