BSP is Board Support Packages. BSP is a middle layer program, which talks with the hardware. End user will not have to bother about what the underlying hardware is. User just has to write the program on top of the hardware.
BSP will provide programming API's to all the components that are implemented on the hardware. A BSP code will be available to users in library format so that one can quickly write sample applications in programming environment and download and test them without knowing too much about Hardware architecture. This will enable the user to get the feel of the device.
A set of commands will be available for user to use the board as out of box product. These commands can be defined as per user specific requirements.