1024 × 768 vs 1280 × 1024
XGA against SXGA, side by side.
1280×1024 renders 524,288 more pixels than 1024×768 — 67% more. They differ in shape too: 1024×768 is 4:3 while 1280×1024 is 5:4, so windows and video fit differently.
The two shapes of the pre-widescreen office. If you're maintaining legacy hardware, note they differ in shape, not just size: 5:4 is taller relative to width than 4:3, so interfaces built for one crop or letterbox on the other. For projector-versus-monitor swaps, check what the software actually renders — much industrial UI of that era hardcodes one of these grids.