Re: power supply project
The primary mode will be a variable, set voltage, with up to the maximum current given, depending on what the powered circuit draws.
Very often the PSU will also have a constant current mode. In that mode, the voltage is varied automatically as the PSU attempts to maintain the set current. This mode might be entered automatically if the PSU is in voltage mode, but the current drawn by the circuit reaches the current limit. In this way the current limit can be used to protect the circuit in the event of a fault.
A good laboratory PSU should have both modes.