All are hand woven on the islands off the Northern coast of Scotland (outer Hebrides).
There are two types of Harris Tweed:
1) Fabric woven from hand-spun yarn.
2) Fabric woven from machine-spun yarn.
Now very few are woven from hand spun yarns as it takes too much time and labour. It is always stamped to that effect in addition to the label which any Harris Tweed always bears. Much is woven in 27" and 28" widths, but also in 54". When damp, it smells mossy and smokey.
Derivation: From one of the islands where it's made "Harris". Trademark.