Binning
Sorting finished chips by what they can actually do. The reason a product family with six different models is often built from exactly one design.
No manufacturing process is uniform across a wafer: dies from the centre and the edge differ in leakage and in how high they will clock, and random defects knock out individual cores or cache blocks. Rather than discarding anything imperfect, every die is tested and dropped into a bin. The one that hits the highest frequency at the lowest voltage becomes the flagship; the one with two broken cores has them permanently fused off and sells as a cheaper variant. This improves yield and produces a ready-made product ladder at no extra development cost. When demand for the cheap models exceeds the supply of defective dies, fully working ones get downbinned — the origin of every story about cores that could be unlocked.