Contexts correspond to UIMA Pipelines. A context is associated with an Annotator (Primitive or Aggregate), or (for an aggregate, also its flow controller).
- There is a "root" context. Aggregates have children and a structure corresponding to the directed acyclical graph of the subparts.
A pipeline's root points to its ResourceManager, which has all the external resources, the CAS Pool, and the extension class loader.
- A single ResourceManager instance might be shared with multiple pipelines.
- There is a variant / wrapper for context for PEARs, which substitutes a class path associated with the Pear
Here's a draft of a new chapter for the UIMA Reference, describing resources (it's incubating as part of the v3 users guide)