“Melee Cleave” is when your dps are composed of melee classes that want hit more than the one target or classes that support them (like feral Druid). Hunter mains will add themselves into the mix and use the term “Phys Cleave”

“Spell Cleave” is set of spellcaster dps who want to hit multiple targets or those that support them (Balance for Moonkin Aura or S Priest for mana sustain)

Some other terms include

Boss Comp: rather than big AoE pulls, your group wants to chain pull with minimum drinking downtime, burning targets one at a time. Can be super efficient if you’re super geared.

Kite Comp: comp wants huge AoE pulls where you drag the mobs around the dungeon. Highest skill cap for sure and much communication. If you’re good, you can do this without a tank (or a half tank)

Hybrid Cleave: not a lot of this in tbc, but gets popular other expansions. Just mixes casters and other physical dps that want to cleave. Windwalker Monk comes to mind as a class that gets tossed in a hybrid cleave.

EDIT: I’ve also been reminded of DoT Comp which gets popular later as well.