Neutral point is basically a refrence point it may be at
any potential difference. i.e. 5V, 10V, 1000V etc.
Take an example of a system where voltage is fluctuating
between 9,950V to 10,050V. and its external body is at
10.000V, when we take Earth as the refrence point. Now
every calculation will include these parameters, but if
take 10,000V as the refrence point/ neutral of the system
then we can say the fluctuations are between -50 to +50V
only and further calculations will be easier then the
Neutral point is a technical term for refrence point
whereas Earth is a typical example .
normally speaking, earth and neutral is having the common
point at generating stations.
But neutral is treated as the "return" path of the supply.
But when we are transferring supply to a long distance , it
needs 4 conductors, 3 for phase and the last one for
neuatral(return).So it is getting expensive ,
so normally we are earthed at the generating stations and
only taking 3 condutors till it reach the i/p of the
Distribution transformer(i/p is delta) and from the
secondary(star) we are starting neutral(altogether 4 wires).
And this neutral is earthed there.
AS FAR AS I'M CONCERNED BOTH SOUNDS SAME. NEUTRAL IS THE
RETURN PATH IN AN ELECTRICAL CIRCUIT. EARTH IS CONSIDERED
TO BE THE COMMON REFERENCE POINT. AND THE NEUTRAL IS ALSO
CONNECTED TO EARTH(GROUND). IN OUR HOME, EVEN IF NEUTRAL IS
CUT, WE COULD USE OUR HOUSEHOLD EQUIPMENTS CONNECTING TO
EARTH. WITHOUT EARTH NOTHING COULD BE DONE, BUT SOMETHING
CAN BE DONE IF THER IS NO NEUTRAL.