A StreamBase interface is a set of definitions of input streams, output streams, Query Tables, constants, named schemas, and table schemas.
As templates to enforce strict compliance with its definitions in new and existing modules.
In conjunction with the Extension Point operator that references an interface and hosts one or more module instances that implement that interface.
StreamBase Interfaces discusses opening and editing interfaces, and the use of interfaces as templates.
Using Interfaces with Extension Points discusses the use of interfaces with the Extension Point operator.