Electronic is a  subject which carries out maintenance and repair functions on facilities associated with aviation telecommunication services,radar services,radar navigation and communication equipment.Radio technical officers also repair and test communication,radar& surveillance equipment .

Electrical maintenance is a subject  which carries out installation & maintenance of the electrical infrastructure to equipment & buildings.they are also responsible to repair and maintain the fire alarm system,power generation & disruption systems & uninterrupted  power supply.

hope this helped you.