As an adjective, subsidiary means additional, aiding or subordinate: in other words, not the main thing. So if you have a main goal, you might also have subsidiary goals - aims which aren't central to your enterprise, but which could support it and which would also be good to achieve.
The noun subsidiary (company) comes from this. In business a subsidiary is a company which is mostly or wholly owned by another company; the other (owning) company is often called the parent. The amount of stock (shares) which the parent needs to hold, in order for the other company to be its subsidiary, is usually around 50% but can vary considerably.
Now that multinational businesses have become so large, it is common for subsidiaries to be major businesses in their own right, often with subsidiaries of their own.
The noun subsidiary (company) comes from this. In business a subsidiary is a company which is mostly or wholly owned by another company; the other (owning) company is often called the parent. The amount of stock (shares) which the parent needs to hold, in order for the other company to be its subsidiary, is usually around 50% but can vary considerably.
Now that multinational businesses have become so large, it is common for subsidiaries to be major businesses in their own right, often with subsidiaries of their own.