Any batch of commercial collagen may consist of collagen obtained from cattle or pork or both.
Sometimes food-grade gelatin may be labelled as to the source. Some so-called "kosher gelatin" may not be gelatin at all but may be agar. This may be labelled as such. Other brands of kosher gelatin may be derived from cattle. I'm not sure of the details. It appears it may be sometimes get approved for kosher use even though it is not from kosher-slaughtered animals. I'm not sure of the details in regard to what kind of collagen, if any, is halal or not, either.
The specific animal that is the Earthly Origin of collagen found in cosmetics, etcetera, is especially hard to determine. The source may differ from batch to batch, produced by the same manufacturer, depending, for example, upon market conditions at the time the collagen is purchased by the cosmetics manufacturer.
According to what I can figure out, collagen is the name given to the certain animal proteins that are found in animal tissues. Gelatin is the name often given to the proteins when they are commercially extracted from such animal tissues. Such an extractive may be called "glue" or "hide glue" also, if for glue is its intended use. Some extractives may be called collagen. Whether they are called collagen or gelatin or glue may be more related to what they are used for, rather than to their chemical nature or biological source. Though food grade gelatine may be filtered and clarified.
You might want to take a look at this page. It is an article at Fibrogen, a manufacturer of recombinant collagen. The company apparently has also developed recombinant gelatin.
According to Materials Handbook by Brady and Clauser, 11th edition (1977), McGraw-Hill Book Co, ISBN 0-07-007069-5...
gelatin [is] a colorless to yellowish water-soluble tastless colloidal hemi-cellulose obtained from bones or from skins and used as... Gelatin differs from glue only in purity. Photographic gelatin is made from skins... "Vegetable gelatin" is not true gelatin, but is algin from seaweed.
Collagen is the gelatin-bearing protein in bones and skins. The bone is dissolved in hydrocholoric acid to separate out the calcium phosphate and washed to remove the acid. The organic residue is called osseine and is the proudct used to produce gelatin and glue. About 25% of the weight of the bone is osseine, and the gelatin yield is about 65% of the osseine... When skins are used, they are steeped in a weak acid solution to swell the tissues so that the collagen may be washed out. The gelatin is extracted with hot water, filtered, evaporated, dried, and ground or flaked.
I think that most commercial gelatin comes from cattle, but I am not sure. Though a significant proportion may come from pork. Same with commercial collagen.