What limits the current that flow to a circuit for a particular applied DC voltage?

The current that flows in a circuit for a given applied DC voltage is primarily limited by the circuit's resistance, as described by Ohm's Law (I = V/R). Higher resistance results in lower current flow for the same voltage, while lower resistance allows more current to flow. Additionally, factors such as the characteristics of circuit components (like diodes or transistors), the temperature of the materials, and the presence of any circuit protection devices can also influence the current.