Common terms in Storm include: Stream, Spout, Bolt, Worker, Executor, Task, Stream Grouping, Topology.
Stream: The data being processed .
Spout: Data source .
Bolt: Encapsulates data processing logic .
Worker: Worker process (a worker process can contain one or more Executor threads).
Executor: Thread that runs Spout or Bolt processing logic.
Task: The smallest processing unit in Storm (an Executor can include one or more Tasks, and the distribution of messages is from one Task to another Task).
Stream Grouping: defines a message distribution strategy . Defines how the Bolt node receives data.
Topology: A network of Spout and Blot nodes connected by message grouping . It defines the topology of computational processing, which deals with the constant flow of messages.