MS wire (Mild Steel) is that it undergoes rusting very easily. GI wire (Galvanized Iron) gives protection against corrosion for around 50 years.
Quality of Wires Used
Use of min 1.50 sqmm wires for lighting circuits and 2.50 sqmm wires for power ciruits. FRLSH wires (Fire Retardent Low Smoke Halogen) ensure highest fire safety.