asset_origin
The origin of a crosschain asset that can be used on this chain.
An asset can be issued on this chain, or a different one. If it is issued on a different chain, it's considered a crosschain asset, and it will have an asset_origin linked to it.
An asset has an asset_origin iff it is a crosschain asset.
The origin of the asset might be different from the issuing chain, although in many cases it will be the same. The origin chain represents a chain that is providing the assets to this chain, considered its parent. Assets can only be transferred from a parent to a child chain and vice versa, and only one parent chain can exist for a given asset. Different assets can have different origins.
When this chain sends assets to chains that are not the parent chain (children), it will keep track of the balance of each child chain through blockchain account entities; the children chain cannot send assets among themselves - they must send them through the parent chain. On the other hand, children chains will not keep track of the parent chain balance.
See also
for more info on blockchain account entities
for information on issuing chains