What is the output impedance of a theoretically ideal op-amp?

A theoretically ideal operational amplifier acts as a perfect voltage source at its output. This means it can supply any amount of current to a load without experiencing a drop in its output voltage. To achieve this perfect voltage regulation, its output impedance must be zero, which translates to 'very low' in practical, real-world components. Having a very low output impedance allows the op-amp to effectively drive subsequent circuit stages, speakers, or other loads without the signal sagging. If the output impedance were high, the output voltage would drop significantly as soon as a load was connected, making the amplifier ineffective.