So I know this topic of tunneling has been discussed hundreds of times on this forum, but I simply cannot find nor deduce an answer to a burning question I have about what happens exactly INSIDE the barrier and how to describe it (preferably in layman's terms.) The problem is basic: A particle with energy E that is impinging on a finite barrier with height V where E < V. There are valid solutions to the wave function which describes the particle before it hits the barrier, inside the barrier, and after the barrier. Now, the solutions before and after the barrier are "wave-like" i.e. they are oscillating sinusoidal functions. However, the solution inside the barrier is not... it is exponentially decreasing. So my multi-part question: What is this "thing" inside the barrier? Is it a particle? If so, why? Does it have single particle properties? Is it a wave? If so, why? Also, why doesn't the solution show oscillating behavior? Isn't QM supposed to describe the simultaneous wave- and particle-like behavior? Any response is appreciated. Thanks for your input guys.