What is the difference between earth and ground in the electrical field?

• Ground is a source of unwanted currents and also as a return path for main currents sometimes. While earthing is done not for return path but only for safety concerns against leakage or residual currents on the system via least resistance path.
• Grounding means connecting the live part (it means the part which carries current under normal condition) to the earth. For example neutral of power transformer. While earthing means connecting the dead part (it means the part which does not carries current under normal condition) to the earth. For example electrical equipment's frames, enclosures, supports etc.
• The purpose of grounding is the protection of power system equipment and to provide an effective return path from the machine to the power source. For example grounding of neutral point of a star connected transformer. While the purpose of earthing is to minimize risk of receiving an electric shock if touching metal parts when a fault is present.

 Grounding is the common word used for earthing in the North American standards like IEEE, NEC, ANSI and UL etc. While earthing is used in European, Common wealth countries and Britain standards like IS and IEC etc.

In simple words, Earthing and Grounding are synonyms. Both are smilar words used for the same thing depending upon geographical location.

They are almost the same

I think the question is about neutral and ground

Depends on where you are. Neutral and ground are the same in house wiring,but at the breaker panel. But they're treated differently everywhere else. Neutral is supposed to carry current, ground is not. And some protection circuitry, such as ground fault interrupters, use this difference to keep you safe.