Deal can be defined as a potential sale agreement or business commitment between seller and the buyer organisation/individual, in which the seller will receive monetary reward in return for the products/services he gives to the buyer.
For example if the selling organization receives a request for quotation for 100 units of Product X, from a potential buyer; then it is a deal. The deal value will be equal to the price of 100 units of Product X is the deal value, and the person who has sent the RFQ will be logged as the contact for the deal.