As a native, I can confirm that when you order a three-way (no I’m not kidding, that’s actually what they’re called) they will absolutely murder it with shredded cheese. Sometimes it’s piled up like 3-4 inches high. They do the same with the coneys too but you can only really stack like 2 inches of cheese on a hot dog bun.
ligatures are when you join two or more glyphs into a single one. For instance, instead of having the two characters = and > to form => if you had ligature support you would see ⇒. Some terminals have support to recognize sequences like => (and others obviously) and turn them into their corresponding ligatures (only for display though, the actual file contents remain umchanged)