What is Capacitive Loading (Intuitive understanding)
But what does it mean when one says,&quot;It is a capacitive load&quot;

It means the load behaves like a capacitor. You have to deliver charge to it before the voltage across it will change.

why output impedance should be low for capacitive loads?

Because if you want to change the voltage across this load, you'll have to deliver a significant current. You need a low-impedance load to deliver a current without the voltage sagging.