In SMC, a range is split into a 'premium' (expensive) upper half and a 'discount' (cheap) lower half, using the 50% midpoint. The idea is to buy at a discount and sell at a premium.
It borrows from Fibonacci thinking: entries in the discount zone of an uptrend, or the premium zone of a downtrend, aim for better risk-reward. It is a guideline for entry quality, not a signal by itself.