Residual vs Leftover - What's the difference?

As adjectives the difference between residual and leftover

is that residual is of, relating to, or remaining as a residue; left over while leftover is remaining; left behind; extra; in reserve.

is that residual is a remainder left over at the end of some process while leftover is something left behind; an excess or remainder.

(-)

Of, relating to, or remaining as a residue; left over.

* residuary

(en noun)

A remainder left over at the end of some process.

(in the plural) Payments made to performers, writers and directors when a recorded broadcast is repeated.

* left over, left-over

(-)

Remaining; left behind; extra; in reserve.

Do you want some of the leftover supplies from the event?

(chiefly, in the plural, usually, of food) Remaining after a meal is complete or eaten for a later meal or snack.

I have some leftover spaghetti in the fridge, so I don't plan to cook tonight.

Not leftovers again.

* When used after a verb (as part of a predicate phrase), use two separate words: *: I can walk for miles and still have energy left over.

(en noun)

Something left behind; an excess or remainder.

It's a leftover from yesterday, but it's still perfectly good.

The entire wheel of cheese is a leftover from the party.