Gelatin

Gelatin is hydrolysed collagen, where collagen is the protein from bone of mammals.

Gelatin is used mostly as a thickening agent, e.g. in gelatin puddings.

It's used in a bunch of soft candy, from marshmellow to gummy things to liquorice.

It's also one way of clearing wines.

Note there are vegetarian/vegan alternatives to most of these uses.

And also to the consistency and thickening use itself -- there are various vegetable gelatins, which is arguably only called that as marketing to indicating what it does.

This includes agar agar (more widely: carrageenan), based on seeweed. It seems for some uses this is a more common source of gelatin-like ingredient, because it's more economical.

For some uses, pectin is also a good substitute for gelatin.

...and when the purpose is thickening, there are various others.

Whether these can be called gelatin depends on recognizability marketing, food regulation laws, and personal pedantry.

Note also that the ingredients are more informative than the bug name (also due to potential allergens).

Kosher and/or halal gelatin - observes the respective rules. In practice is often fish based, sometimes seaweed based, but may still be animal.

'Vegan gelatin' might be agar agar/carrageenan, cornstarch, pectin, xanthan gum

See also:

• https://en.wikipedia.org/wiki/Gelatin
• https://en.wikipedia.org/wiki/Vegetarianism_and_wine