It really depends on the band. Take Scar Symmetry, a band you haven't heard of (probably). Its death metal bt has clean vocals in many places. And sometimes the lyrics are very good. Opeth is sort of Symphonic Death Metal but is absolutely the best metal band on the planet for quality.
Here we go sage

NWOBHM: This was the first kind of Heavy Metal and basically is like Iron Maiden and Judas Priest, not extreme but very much like metal and rock mixed.
Thrash: Relies on fast tempos, not as fast as speed metal but very fast, with loud distorted guitars, with complex note patterns. Often features growled vocals. Good example is The Evil Has Landed by Testament.
Speed Metal: Basically patented by Motorhead and Anthrax in somewhat different styles. Very fast rhythm and a very punky attack, but with massively fast riffs. Probably the second hardest type to play after thrash. Ace Of Spades by Motorhead and Indians by Anthrax are your examples.
Black Metal: Genre basically made by Venom then made popular by Slayer. Like Death Metal but less extreme and with sung vocals. Varies a

of a lot though. Two examples- My Twin by Katatonia and War Ensemble by Slayer are our examples.
Death Metal: A diverse range of genres come under this but it is mostly about very growly vocals and extremely heavy riffs. Can also be wonderfully well done as proven by a few band such as Opeth, Meshuggah, ISIS and Scar Symmetry. Our most generic example will be Bleed by Meshuggah.
Power Metal: A metal based off NWOBHM guitar and rythm wise but with higher guitar and cheap choir sound effects :P. Example is Mr. Torture by Helloween.
Nu Metal/Post Grunge: Characterised by rap and slowish industrial sounding riffs, this type of metal is by far the newest. Example is Stricken by Disturbed.
Progressive Metal: Scorpion loves this cause of Dream Theatre. Thrash metal with more progressive rock style riffs and keyboard backing very often.
Stoner: Basically rock, not very metallic to be honest...
Sludge: Slow, grungy rhythms and strange styling. I'm no expert here but Mastodon is your band example.
Hope my guide helped you Sage

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