Once we accept that, other than the IEEE's SRS (Software requirements specification) document, there is no standard name or form for a requirements document we can begin to look at the words themselves for guidance.

 

Using the IIBA's BABOK v2.0 as a guide, functional requirements are the behaviours of the solution - things it must DO for the end user. A BRD or Business Requirements Document is many things to many organizations - from catch all for all requirements to a high-level list of capabilities. I will use the later definition, again in keeping with the BABOK's definitions. Business Requirements are organizational needs expressed by the company its self. They are goal oriented, strategy and tend to be high-level statements that will drive one of more projects.

 

I hope that was helpful

 

Perry McLeod