Difference between voltage and current

 Current:
             It is the rate at which electric charge flows past a point in a circuit. 
Voltage :
           It is the electrical force that would drive an electric current between two points.

Comparison chart

Current versus Voltage comparison chart

	Current	Voltage
Symbol	I	V
Definition	Current is the rate at which electric charge flows past a point in a circuit. In other words, current is the rate of flow of electric charge.	Voltage, also called electromotive force, is the potential difference in charge between two points in an electrical field. In other words, voltage is the "energy per unit charge”.
Unit	A or amps or amperage	V or volts or voltage
Relationship	Current is the effect (voltage being the cause). Current cannot flow without Voltage.	Voltage is the cause and current is its effect. Voltage can exist without current.
Measuring Instrument	Ammeter	Voltmeter
SI Unit	1 ampere =1 coulomb/second.	1 volt = 1 joule/coulomb. (V=W/C)
Field created	A magnetic field	An electrostatic field
In series connection	Current is the same through all components connected in series.	Voltage gets distributed over components connected in series.
In a parallel connection	Current gets distributed over components connected in parallel.	Voltages are the same across all components connected in parallel.

  

Relationship Between Voltage and Current

Current and voltage are two fundamental quantities in electricity. Voltage is the cause and current is the effect.

The voltage between two points is equal to the electrical potential difference between those points. It is actually the electromotive force (emf), responsible for the movement of electrons (electric current) through a circuit. A flow of electrons forced into motion by voltage is current. Voltage represents the potential for each Coulomb of electric charge to do work.

Series and Parallel connections

In a series circuit

Voltages add up for components connected in series. Currents are the same through all components connected in series.

Electrical components in a series connection

For example if a 2V battery and a 6V battery are connected to a resistor and LED in series, the current through all the components would be same (say, 15mA) but the voltages will be different (5V across the resistor and the 3V across the LED). These voltages add up to the battery voltage: 2V + 6V = 5V + 3V.

In a parallel circuit

Currents add up for components connected in parallel. Voltages are the same through all components connected in parallel.

Electrical components in a parallel connection

For example if the same batteriesare connected to a resistor and LEDin parallel, the voltage through the components would be the same (8V). However, the 40mA current through the battery is distributed over the two paths in the circuit and get broken down to 15mA and 25mA.