What is the Difference Between Current Density and Linear Charge Density?

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Current density refers to the flow of electric charge per unit area, while linear charge density indicates the amount of charge per unit length. In current density, the movement of charge occurs in a conductor, which typically has a background of positive charges that maintain overall charge neutrality. In contrast, linear charge density does not necessarily involve a conductor and lacks this neutralizing effect. Understanding these differences is crucial for grasping concepts in electromagnetism. The discussion highlights the fundamental distinctions between these two types of charge densities.
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What is the difference between current density and linear charge density?
 
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Two things.

Basically, current density is movement or flow of charge per unit area and linear charge density (as it says) is the amount of charge per unit length.

It might help you to avoid confusion if you remember that in the case of flow of charge (current in a conductor) there is usually a background of positive charges in the conductor that keep the conductor charge-neutral overall.
With a linear charge you have no such cancelling factor - it's often not even a conductor.
 
thanks.. nice hints
 

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