What is meant by duality and how is it different from nonduality 🤔 Anyone able to explain in a simple way ? [Spirituality & Religion]

I understood duality when I thought about the military slogan that was pushed at my unit. I think President Reagan started it ....

"Peace through superior fire power."

I like that, and I agree. I'm a pacifist and my fellow pacifists and I will obliterate anyone who threatens our 'peace'. Ohmmm Ohmmm Ohm mane padme ohm........................
Namaste brothers and sisters. 🙏

https://nonduality.org/what-is-nonduality/

In my mind duality equals Yin/Yang.