Topping?

I'm about twenty days into growing and I was wondering when the right time to top the plant was. And also what topping actually really is and what does it do to the plant? Any help is greately appreciated.

its a good time yes!! you pull of the newest growth. buy doing this you will stop the top growth and two new top growths will start coming out ouf the top. resulting in a bushier plant with two or more top buds. I will always topp all my plant since I grow in a smaller space

Topping will stop the vertical growth of the plant, and dedicate its growth to the nodes left on the plant.
You can top the plant whenever you like, whatever size you want, how many nodes you want. all up to you