The printer icons "Brother DCP-115C USB" and "Brother HL-5250DN" are the "built-in" drivers (Inbox drivers).
The 'built-in' driver (Inbox driver) is the preinstalled driver in the OS.
By connecting a Brother product to your Windows Vista® computer, the appropriate printer and scanner drivers (if applicable) are installed automatically without any user-intervention.
The other printer icons "Brother DCP-115C USB Printer" and "Brother HL-5250DN series" are the drivers that Brother will provide on the web or on the CD-ROM which is supplied with the product. That driver is called "Brother original driver".
What is the difference? Which driver should I use?
The difference is its functionality.
The "built-in" drivers (Inbox drivers) may not have the full functionality that Brother original drivers will have.
For example, the following is the printer driver properties of the "built-in" printer driver (Inbox printer driver) of DCP-115C.