The following data explains the important aspects connected with the electrical parameters like voltage and current, the content also explains in simple words how to differentiate the two parameters.
What is Current
It is the number of electrons flowing at any instant through a conductor or across the positive and the negative of a conductor
What is voltage
It is the pressure/speed/force at which the electrons are flowing through a conductor across the positive and the negatives poles of a conductor.
Relation between Voltage and Current
Current may be compared to mass of a body and voltage with the speed at which the body is able to move. Naturally the mass becomes effective only when it moves. Now suppose the body rams with an object, the extent of damage will depend on the speed of the body.
Similarly current itself cannot affect a circuit but will depend on how much voltage is accompanied with it.
That’s why the voltage spec of a particular electronic component becomes more critical than its current rating.
For example, an LED specified for operating at 3 volts can be operated safely irrespective of the current input as long as the voltage remains within the specified range, however if the voltage crosses the specified limit, the current becomes critical and instantly damages the part if not restricted using a resistor.
Another relation between voltage and current may be understood by analyzing the following example theory: Suppose, a plastic ball is thrown toward you at some speed, you could easily stop it with your hands, forcing its speed to nullify. However if an iron ball would be thrown at you at the same speed, you wouldn’t dare to stop it rather if you tried, you would be smashed or thrown away aside.
In the above example we can relate the mass (plastic or iron) with current and the speed with voltage, meaning if current is very low the voltage will drop when brought across a load which is not as per the specs or wrongly connected or if a short circuit is made. Conversely, in the above case if the current is huge, the voltage wouldn’t drop, rather would burn down the connected load or cause a fire if the output is short circuited. Considering another example, current may be compared to a bullet and voltage to a gun.