Difference between BRS and FRS

The main difference between brs and frs is that a brs tells the whole
requirement(story) whereas the frs tells the sequence of operations to
be perfored by a single process.

BRS is actually a document that covers the business aspect of a requirement on a broad level. For eg: lets consider that you want develop a new website. Your BRS would address what business is your website being built for. Lets say it is a website like ebay and it allows people to shop online. This would be your business requirement covered in the BRS.

Now the FRS would actually address each function that the website provides in order to make the shopping experience of the people visiting the website efficient and easy. Not just this it would also address issues of security etc that may need to be built into this wedsite.

Both the BR and FR can actually be addressed in the same document. However, this depends on the organization.

Both BRS and FRS are made by the BA who captures the requirements from the end user. A developer would be involved in making a technical document which would address the technical design of the website which the BA may or may not concern himself with.