I have got this bottle of wood polish (an Indian brand called sheenlac). I also later got Varnish (PU). Are both required to be applied after sanding or just the wood polish would do ?
Wood polish is usually an oil, wax, or oil and wax treatment. Waxes include carnauba, parrafin, beeswav etc.; oils could be tung oil, linseed oil, mineral oil, petroleum oils, or oils from animal fats. Polishes help protect wood but are different from varnish. Varnish (whether natural or synthetic) create a fairly hard and durable surface coating, which could then be maintained by periodically applying a polish.