RCBO (Residual Current Circuit Breaker with over current protection) -This is a combination of an RCD and MCB in one unit.

BS7671/18th Edition - This is the national safety standard for electrical works (if comparing to a Gas Engineer, that Engineer would have to be compliant to the Gas Safe register). 

Consumer Unit -This is typically referred to as a 'fuse box'.

Earthing - Earthing will reduce the risk of an electrical shock if in the event you touch any metal parts within the property when a fault has arisen. Earthing will provide a path for any faulty electrical current which will allow the current to safely travel through the earthing cables and in turn the safety cut out device will operate turning the electricity off.

RCD (Residual Current Device) - An RCD is designed for safety, if an imbalance is detected in an electrical circuit protected by an RCD it will automatically cut of power. 

MCB (Miniature Circuit Breaker) - MCB is a type of automatic switch that interrupts the flow of electricity current and turns off in the event of over current being detected. 

MEIWC (Minor Electrical Installation Works Certificate)