How should we understand control the voltage, not the current ?

[Alex_Sanders]

How should we understand "control the voltage, not the current"?

And provide "roundabout" for spikes? I mean seriously, isn't V and A closely related? You regulate one, you end up regulate both?

 

[Jony130]

No, when you regulate the voltage you end up with constant voltage not the current.
Simply ohms law I = V/R
Despite the fact that we have a voltage which does not change, but the load current will change as load resistance is changing.
For V=10 and load resistance change from 1K to 100R causes the change in load current from 100mA to 10mA. Despite the fact that the voltage doesn't change at all.