What is Consciousness

It has been hard to find a good "explain it like I'm 5" summary of consciousness on the internet so I decided to write one, in part to help me learn more about it.

What is consciousness?
The simplest definition I've found is that it's the experience of feeling something. Eating ice cream feels like something, being happy feels like something, and seeing the color red feels like something. No one knows where consciousness comes from, but there are lots of fun theories that fit into three broad buckets:

Materialism
Materialists believe that everything is physical stuff. Subatomic particles make up atoms, atoms make up molecules, molecules make up cells and eventually you get trees and frogs and humans and somewhere in there you also get consciousness. Maybe consciousness emerges from complex brain processing or maybe it is the experience of the brain thinking about thoughts or maybe it lives in some part of the brain we don't understand yet.

Dualism
Dualists believe there is physical stuff and there is some other distinct thing called consciousness and the two interact in some way. Perhaps every atom comes paired with a small amount of consciousness (eg more complex things have more consciousness) or maybe our physical brains act like antennas that tune into consciousness originating somewhere else creating a bridge between two worlds.

Idealism
Idealists believe that consciousness is fundamental. This is my favorite because it flips everything I think I know upside down, like a modern version of finding out the Earth is not the center of the solar system. These theories imply that consciousness creates physical stuff, not the other way around. I like to visualize this as us being like pixels on a computer screen and thinking the screen is all of reality, not realizing there's an underlying computer that sets the rules and projects the screen.

This is about to take a weird turn, but if idealism is correct it could explain why we haven't been visited by aliens. Maybe as part of becoming technologically advanced enough to travel through space, aliens discover that we are all one consciousness experiencing itself through different forms. If that's the case, aliens visiting humans prior to us discovering this truth would be like a pregnant mother trying to visit her unborn baby in her womb. If we are the same consciousness as aliens having a human experience, maybe they let us follow the natural course, like a mom allowing her baby to grow until it's ready for birth.

Maybe elements of all three theories are correct and we are like fish trying to understand the universe. The material world could be our immediate reality like water is to a fish, consciousness could be the next layer out that we're just barely able to glimpse via meditation, psychedelics, quantum, etc. like a fish being caught and released and trying to explain it to their friends, and there are more layers beyond that, similar to how outer space is multiple degrees of comprehension removed from a fish. Even if we understood the layers, I like to imagine they engage in a cycle of death and rebirth, influencing each other and remixing, similar to the dance of nature on Earth.