The difference between a product and a project is that the former is often the result of the latter.
For example, you might work on a software project which goal is to create an accounting system to be sold for small businesses.
The project is the work you spend building the accounting system, the accounting system is your product.
A project does not always result in creating a product, a project might also create a service (for example, creating a customer care service), etc...
I hope that helps.