Requests for proposals are similar to requests for information in that they are a mechanism that is utilized throughout and across many professional industries, and are not restricted in utilization to that of project management. In many industries, requests for proposals are solicited by buyers or purchasers of long term and or elaborate projects or products to sellers or purveyors of such in the attempt to determine what the different ideas and strategies each of these purveyors may have. Typical lint he area of project management, the request for proposal functions very similarly in that the request for proposal serves as a type of procurement form that is used for the purpose of requesting or soliciting proposals from prospective purveyors or sellers of a series of products and or services. While this definition is very broad, in some the definition may in fact be much narrower, depending on the particular application area that it is being utilized in reference to.
This term is defined in the 3rd and the 4th edition of the PMBOK.