effective earthing and resistive earthing

Effective earthing (grounding, for us westerners) means the electrical system star / neutral point has a direct, solid connection to earth. Resistive earthing has a resistor between the star point to earth. The resistor is used to limit earth faults to a lower value, so as to lessen likelihood of damage to electrical apparatus and allow detection of the fault by sensing the voltage drop across the resistor due to the current flowing through it. Remember that under normal conditions, the neutral will have little to no current flow.

Resistance grounding may be high resistance (limits current to about 5 amps, often used in systems 600V and under, but sometimes in medium voltage) and low resistance (usually limits current to 400 amps, with the resistor rated to handle this current for about 10 seconds - more often found in MV systems). Do a search on "resistance grounding" and "NGR" (neutral grounding resistor) and you will find a lot of info.