The term is used as a very loose categorization, but is usually used to describe artists playing a style of heavy metal music with an "alternative" approach. Many bands categorized as "alternative metal" are equally influenced by alternative rock and heavy metal.
Initially alternative metal appealed mainly to alternative rock fans since virtually all 80s alt-metal bands had their roots in the American rock underground scene. Alt-metal bands commonly emerged from hardcore punk (Corrosion of Conformity), post-punk/noise rock such as Big Black, Fugazi and Sonic Youth along with others such as Helmet and White Zombie, grunge (Alice in Chains, Soundgarden), industrial (Ministry, Vardis, Nine Inch Nails).
These bands never formed a distinct movement or scene; rather they were bound by their incorporation of traditional metal influences and openness to experimenting with the form. For example, Jane's Addiction utilized performance art and a bohemian aesthetic, Corrosion of Conformity, The Melvins and the now defunct grunge band Soundgarden had a fondness for subverting '70s metal, and Faith No More, along with Living Colour, injected funk and hip hop into their brand of alternative metal, while Primus incorporates an obscure Residents-esque touch.
Bradford Phillip Delson
Brian Phillip Welch
Joshua Michael Homme