Quick answer
A speaker cable carries the audio signal from an amplifier to loudspeakers. The keys to good sound are conductor quality and the right thickness: high-purity copper lowers resistance, and a thicker conductor (lower gauge) is better for longer runs or higher power, giving distortion-free, attenuation-free sound.
Look for bright-annealed, electrolytic-grade copper and quality insulation. APAR's Tarang Shakti Speaker Cable uses electrolytic-grade copper with transparent FR-PVC insulation for clear, high-fidelity audio.