Battery sense is used for accurate battery terminal voltage measurement, hence correct charge levels and  HVD/LVD actions.
A cable carrying load will have a volt drop along its length and the voltage will be different at either end depending on whether the solar charge or load is active.
A separate small diameter cable is connected between battery terminal and Sense terminal.
This cable is not used as a load cable and has virtually zero current = no volt drop.
It must be used where there is some distance between charger and battery.
Temp comp is used for measurement of battery temp and correct charging levels ie SG etc.
See the Solar Batteries range