The difference is a Letter of Intent is basically a letter stating the kind of offer you are contemplating in making. Usually it contains what I call the GENERAL items of price, terms and closing date. Most of the other legal STUFF is left out.
The Letter of intent / LOI is a document that many refer to, but actually is poorly understood. Without proper understanding of the document you might find yourself making mistakes in your business that will cause you great embarrassment.Few traders and brokers realize that the Letter of Intent is not a standard document in International Trade.