Two documents with different jobs
A quote
A quote is a priced offer for a defined scope. Line items, quantities, rates, taxes, delivery terms and a validity date. It answers one question: what will this cost. It assumes the buyer already knows what they want and is comparing numbers.
A proposal
A proposal is an argument. It restates the buyer's problem, sets out an approach, defines scope and exclusions, gives a timeline, introduces who will do the work, and includes commercial terms. It answers a different question: why you, and why this way.
