Distillate is an extract that has been through distillation, leaving practically nothing but one target compound — no waxes, no chlorophyll, no residual solvents and no aroma.
It is made by short-path distillation under reduced pressure. Lower pressure lowers the boiling point, so the work happens at a temperature that does not scorch the material.
The consequence: distillate has no flavour or smell of its own. It looks like a clear to amber syrup and behaves predictably. That is why cartridge liquid is made from it — it doses precisely and does not crystallise in the heating element.
Flavour is put back by adding terpenes. Hence the difference between a cartridge with botanical terpenes and one with the original terpenes reintroduced.