This is the driver (PCL) for Brother printers. It is a utility that converts the data to be printed to the specific fax/printer. The purpose of the printer driver is to allow programs to do printing without being aware of the implementation of each printer model. Whenever you print a document, the driver sends data to the printer with the correct commands. Windows will install generic printer drivers, however to get the most out of your printer, the Brother driver should be installed.

brlmfa4b.dll is loaded as dynamic link library that runs in the context of a process. This particular version is usually found on Windows 7 Home Premium (6.1.7601.65536).