Can someone explain Shrodingers' Cat (experiment?)

I tried to read the Wikipedia article but most of it just went over my head. Can someone explain it in terms I can understand (I have a basic knowledge of physics, chemistry and biology from high school). Thanks

Basically, a cat is placed in a room which is completely isolated from the outside world. Inside the room with it is a bit of radioactive material and a Geiger counter. When the material decays in say, an hour, the counter will detect it and poisonous gas will be released. So at the end of the hour, is the cat dead or alive? Without looking inside the room you can never know, but if you look inside the room you're interfering with the experiment. So according to quantum mechanics, the cat is both dead AND alive at the same time until you look inside the room. This is called the Copenhagen interpretation. On a more physics-y level, the basic principle is that a particle may exist in several different states at one time, but when it is observed, it is forced to "choose" a state to be in permanently. This could be compared very roughly to the phrase "If a tree falls in the woods and there's nobody there to hear it, does it make a sound?". It's impossible to know

There's an episode of Big Bang Theory that explains this very well. Schrodinger put a cat in a box that no one could see inside of. At a random point in time, the cat was going to die (I think it was from poison). No one knows when the cat is going to die. The cat cannot be called dead nor alive until someone looks in the box. Therefore the cat is considered both dead AND alive until someone looks.

If this doesn't help, then find the episode of Big Bang Theory and watch it.