You might never have considered it consciously, but the jiggly, rainbow-colored gelatin desserts you loved as a child -- despite their artificial appearance -- are actually sourced from animals. Conventional gelatin is produced from the hooves, hides and bones of cattle and hogs, after the more-desirable portions are used. That represents a problem for households that keep kashruth, the observances that collectively make up kosher food handling. As a result, many manufacturers offer kosher versions of gelatin.
Kosher by Degrees
Traditional forms of kosher gelatin fell into two categories. One variety was certified to be made only from cattle hides, with no pork present. The other type was made from alternative gelling agents, such as fish-derived isinglass or agar-agar, which is derived from seaweed. Neither was entirely satisfactory. Strictly observant households objected to the beef-derived product because the animals were not necessarily slaughtered to kosher standards, while the gelatin alternatives were unpredictable and unreliable in their gelling strength.
The obvious answer was to manufacture genuine, animal gelatin entirely from the hides of kosher-certified animals. This meets the most stringent of kosher and culinary standards, and can be used interchangeably with conventional gelatin by home cooks and industrial food processors alike. Oddly, because it's so highly processed, it's even considered "pareve" -- neutral -- and can be used with dairy products, unlike other meat-derived foods. This clears the way to using kosher gelatin in panna cotta and other thickened custard-like desserts containing milk or cream.