Check what differences for VESC PPM Control Modes and find suitable control mode for your usage:
Off: Nothing, motor if off and not working;
Current: With brake and reverse, it controls the current to the motor and consequently the torque, it gives torque control (acceleration) but does not limit or try to control the speed, it control the currents flow instead of the speed. With just a slight of throttle the motor will spin at maximum rpm immediately. When load is added, the motor rpm will slow down. This allow you to steep climb hill at quite low speed as the power flow of your board is in you hand. The disadvantage of current control is if you maintain your throttle and the road suddenly goes down hill, you will accelerate. At some point it could be dangerous in dual drive motor when one wheel is loosing traction, the wheels that looses traction will spin at max rpm immediately and when it has traction again might cause a slight drift movement.
Current No Reverse: Save as current mode but no reverse function. Note that centring the now will give half throttle.
Current No Reverse with brake: No reverse, but centre is zero torque. Reversing will brake, but not change motor direction.
Duty cycle: Duty cycle or voltage control. What most hobby ESCs use, it controls the duty cycle (voltage) to the motor and consequently the speed, it gives rough speed control (velocity) but does not control the current (the maximum set motor current will be used to accelerate or decelerate the motor to the commanded duty cycle). Will not increase the duty cycle to maintain the same speed when under heavy load.
PID Speed Control: The throttle command is interpreted as a speed set command and closed-loop control is used to maintain that speed. “PID max ERPM” sets what max throttle should be interpreted as. It controls the ERPM (velocity) of the motor, tries to always make the motor turn at the commanded speed irrespective of the load. Duty cycle and current will change to maintain set ERPM. Requires tuning for best performance.
Current control will change your acceleration, duty cycle will control your speed (but acceleration can be very harsh), PID will act similar to duty cycle.