What exactly is the physical significance or meaning of Current density?
The formula $J=\frac{I}{A}$ is one thing but what does this represent, I am unable to visualize it or feel it.
We have already defined current as charge flowing through a cross section per unit time as current but now what does current density mean?
For example, while deriving the formula for magnetic field due to a infinite sheet, I came across the term take current per unit area as $J$, what information does this give me? I am really confused regarding current density and I don't have any intuitive feeling regarding it. How should I think about it? Please help.