Quote by tomothy
'If particles also behave as waves, then what is oscillating?'
I'm fairly sure that most people would consider this a nonsensical question. But I'm not sure why and I was hoping someone could clear this up for me.
My thoughts are:
The wave function is just a mathematical model, so don't panic.
Particles behave as waves as well, stuff isn't really either, it could really be something in between but nobody knows, so don't panic.
Thanks in advance.

Do you mean "what does it mean for ψ to oscillate in space?" This means the probability of finding the particle changes as you move through space at a given instant in time. The particle is more likely to be in some areas than others.
Do you mean "what does it mean for ψ to oscillate in time"? This means that, in a given region of space, the probability of finding the particle in that region changes over time (becoming more likely and then less likely and back again if the oscillation is sinusoidal).
This is a rather barebones explanation, and you need to be careful about you mean by "probability," but I think it conveys the basic answer to your question.