Libraries and related organizations group together in a variety of ways to get their work done. They consort where there are scale advantages: to lobby, for example, to negotiate and license, to reduce costs, or to build shared infrastructure.
The library does not have a singular network presence. There may be a main website, but the library also syndicates its presence to other venues (e.g. RSS), has unbundled to social sites (e.g. Facebook), and sources activity in the cloud (e.g. LibGuides).
The collection remains central to the library experience. However, as library services evolve beyond the collection so it makes sense for discovery services to represent more of what the library does and can provide - to move from 'full collection discovery' to 'full library discovery.'