The difference between ideal voltage source and the ideal current source

The ideal voltage source maintains a fixed voltage, and zero internal resistance. A current source is supposed to support any amount of potential difference across its terminals, and supply the same amount of current into the nodes it is connected to. No physical current source is ideal, just as ideal voltage sources.

An ideal voltage source provides no energy when it is loaded by an open circuit (i. e. an infinite impedance), but approaches infinite energy and current when the load resistance approaches zero (a short circuit) ... An ideal current source has an infinite output impedance in parallel with the source.