These documents are similar and are often used interchangeably. While they vary a bit from each other, they are used for the same purpose which is to show intent and an agreement to agree. Most are considered "nonbinding" unless the wording is included to make it binding.
Understanding what a Letter of Intent is and when to use them is a bit confusing. But basically, this letter just means you are serious about continuing towards a purchase and that you want the other party to stop entertaining other offers. Our Letter of Intent template is suitable for all states.