The total weight of the car is determined by adding the scale weight of each corner (car sitting on 4 individual wheel scales). Dedicated race cars use these individual numbers to tailor each corner spring rate.
The weight on each wheel is determined by the actual weight, how it is distributed in the car, spring rates, shock bump rates, sway bar pre load ride height, rake etc. etc. It is what it is but varies. Statically you can make suspension adjustments or move things around in the car such as relocating a battery from the front to the rear to change corner weights.
F/R bias is the additon of the front wheel weight as compared to the weight on rear wheels. Likewise side to side. It is desirable but almost impossible to get all 4 corners of the car to weight the same
The most important suspension mesurement is the Cross Corner Weight % Difference. Cross Corner Weights are:
RT Front + Left Rear weight and
Lt. Front + Rt Rear weight.
Even though the corner weights can not usually be equalized it is possible to equalize the cross corner weights close to 50/50 and reduce the % Difference to Zero.