Nothing. Business transactions should be spoken about in the plainest possible way. People using terms like this come across as lacking credibility (at least to me).
Besides, a deal is never crafted, it is always negotiated.
Crafting evokes a singular emphasis whereas a deal always involves two parties.
I would avoid using this term and avoid anyone who describes themselves as having this ability
Back in 2001, Havard had a Deal Crafing Toolkit what was used in some classes but I have never seen it beyond that reference. Even there the ultimate goal was to demonstrate the tension between creating and claiming value in negotiation.
"Deal Crafting" seems to imply that a particular deal can be manipulated in some way which is not what you want to happen in today's transparent environment. Not sure how the term is being used in your world but many could consider it a very negative phrase. My advice is to be very careful in using this term.
"Deal Crafting" accurately describes what I did for years as a business broker. Most business owners are expert at delivering their product or service, but most know very little about the purchase or sale of a business. This leaves two inexperienced and somewhat ignorant parties trying to fumble around and make a deal.
As a professional broker, I would add value by first assessing a realistic selling scenario for the business and then setting realistic expectations in the seller's mind. Once a buyer was found, I would work to educate the buyer on the process of buying a business and show them examples of how deals can be structured. By communicating with both parties and understanding their goals in the negotiation, I often made suggestions which lead to an ultimate successful deal.
I would imagine that this scenario can play out in many areas of business where you have infrequent transactions or inexperienced participants. For example, specialized purchasing consultants exist to help companies acquire machines and equipment that they may not regularly purchase.
Could you not say that a designer or decorator is helping to 'craft' the chef's new restaurant? There certainly are people out there who specialize in coaching or shepherding a negotiation. To the point of the earlier respondents, I ran into a large number of charlatans and con artists who claimed to be able to do what I did but could not.
I would recommend that you ask for references from both sides of past deals and follow them up if you ever go looking for this type of expertise.
Hope this helps.