Current density as word itself suggests is the density of current. It is denoted by the symbol J
. In the field of electromagnetism, Current Density is the measurement of electric current charge flow in amperes per unit area of cross-section (m²). This is a vector quantity, with both a magnitude scalar and a direction. An electrical current flowing through a solid, and having units of charge per unit time per unit area measured in the direction perpendicular to the flow direction.
It is about how much current is flowing across the given area.