What is domain logic?

Question

What is domain logic? The Wikipedia page for domain logic redirects to business logic. Are they the same thing, and, if not, how do they differ?

Answer 1

Let's cover a scenario.

You have a client for XYZ restraint and he wants you to make his system online.
Where user can place an order online, track them, make payment etc.

For a client point of view this system would be called Business Idea while "place order online" said to be one of the business process and if user place order online, client wants each detail of user, want to display it on screen etc said to be Business logic.

Now you will model his business idea into your point of view in a way that your system can accomplish his all business process or his complete business idea said to be Problem Domain or Application Domain or Domain of your Application.

Now you will first identify all the business processes. And identify entities or object to accomlish business processes. Those object said to be Business Obect or Domain Object and method or logic that implement business process like placeOrder said to be Domain Logic.

So business logic is what client wants because its in client business domain and domain logic is how you implement it. because it's in your application domain.