It can be summarized in one sentence: the brand is embodied by the trademark.
Trademark right is the legal protection of brand.
Trademark is the legal form of brand.
If an enterprise wants to be big, long-term or even listed, it must have a trademark. A trademark needs to be registered with a business license, and a brand is just synonymous with nothingness.
The trademark is bound to the business license, which is the company. Brands can be passed down for a hundred years because of trademarks.