If a software application designs for a specific client, then it is called PROJECT. OR
If any organization is developing the application according to the client specification then it is called as project
If a software application is design for multiple clients, then it is called a PRODUCT. OR
If any organization is developing the application and marketing it is called as PRODUCT.
The only difference we come across during the project testing and product testing is :
In project testing we go through the Alpha Testing, Beta Testing, User Acceptance testing whereas in product testing we don’t have this.