Explain the difference between an unsolicited and a solicited proposal. Also explain the difference between an internal and external proposal.

A solicited proposal is when the customer asks your for a proposal,while a unsolicited proposal is when you take the initiative to send a potential customer a proposal that was not requested.

A internal business proposal popularly referred to as a  business Case, is a document directed at other parts of the organization. This acts as a tool for internal change within the organization. An external proposal is directed at potential clients or customers.