The simplest application of RUSLE2 is to assume a simple uniform slope.  RUSLE2 estimates the amount of sediment leaving the slope length assumed in the RUSLE2 computation.
Soil loss is the net mass of sediment removed from a particular portion of the slope.
In this simple uniform slope, sediment yield, which is the amount of sediment delivered to the end of the slope equals soil loss.  If deposition, like the deposition that occurs on concave slopes had occurred, sediment yield would have been less than soil loss.
Soil loss is expressed in unit of mass divided by the area that produced the soil loss.