How do you define a bait vs a lure? For example, what is the difference between a bait and a food lure? Seems they both start with a base ingredient and then from there are mixed with various additives.

Concentrations of odor and the amounts used would be a defining factor in lure vs baits. Both can do the job. Lure and baits give you options and choices. Lure can give you more specific animal response and reactions for different types of sets.All will create interest and curiosity to some degree.

To me, a Food lure IS A BAIT.....since it appeals to hunger/hunting response. Baits in my mind are food based. I used to make a liquid bait, that squirted outa the bottle, for instance.

...and Lure....... is typically a gland or curiosity or territorial response...to me.

Some can actually have some of BOTH as well.