A plan or suggestion, especially a formal or written one, put forward for consideration by others.
“A set of proposals for a major new high-speed rail link”. Synonyms as scheme, plan, project, presentation, suggestion, draft, tender, recommendation.
Proposal is a plan or suggestion or your planning. A business proposal is a written offer from a seller to a prospective buyer.
Business proposals are often a key step in the complex sales process. A plan or an idea often a formal.