Composite Adapter
From DocDataFlow
At the lowest level, Crawler has two main classes of adapters: atomic adapters and composite adapters. A composite adapter is any adapter that is constructed from smaller sub-adapters (themselves either composite or atomic).
Inside a composite adapter, the sub-adapters can be arranged in many different ways. For example, they could be chained together in an adapter chain or they could all be presented as mutually exclusive selections in a a selector