Semi-chisel vs full-chisel chain
The two main cutter profiles on saw chain: full chisel has square-cornered cutters that slice fastest in clean wood, while semi-chisel has rounded corners that stay usable much longer in dirty or frozen conditions. The cutting corner geometry is the only real difference.
Choose full chisel for clean softwood felling and bucking where speed matters and the chain can be touched up often; choose semi-chisel for storm work, dirty stumps, frozen timber and anything near soil, where a square corner would be gone in minutes. Semi-chisel is also more forgiving to file freehand, since the rounded corner hides small errors that would show up immediately on a chisel cutter. A third category, low-profile or micro-lite chain, prioritises kickback resistance and is what most consumer saws ship with regardless of profile.