In the context of business, when we think of large reputable companies we tend to think of good quality products, reliability, openness, and they give us confidence in what they do, and in what they say.
We, therefore, have confidence in their brands, we recognise the brand, we have confidence in the history of the product, and all of this reduces uncertainty and enables us to purchase with confidence.
However the brands may have associated brands, for example, a company may make a particular product for which it is renowned, but the company may also make other products, and we judge the quality of those other products against the established product. We call these other products the meta brand.