Add back in commentary at top of pipeline file

src/crewai/pipeline/pipeline.py

@@ -11,6 +11,38 @@ from crewai.pipeline.pipeline_run_result import PipelineRunResult
 Trace = Union[Union[str, Dict[str, Any]], List[Union[str, Dict[str, Any]]]]
 
 
+"""
+Pipeline Terminology:
+Pipeline: The overall structure that defines a sequence of operations.
+Stage: A distinct part of the pipeline, which can be either sequential or parallel.
+Run: A specific execution of the pipeline for a given set of inputs, representing a single instance of processing through the pipeline.
+Branch: Parallel executions within a stage (e.g., concurrent crew operations).
+Trace: The journey of an individual input through the entire pipeline.
+
+Example pipeline structure:
+crew1 >> crew2 >> crew3
+
+This represents a pipeline with three sequential stages:
+1. crew1 is the first stage, which processes the input and passes its output to crew2.
+2. crew2 is the second stage, which takes the output from crew1 as its input, processes it, and passes its output to crew3.
+3. crew3 is the final stage, which takes the output from crew2 as its input and produces the final output of the pipeline.
+
+Each input creates its own run, flowing through all stages of the pipeline.
+Multiple runs can be processed concurrently, each following the defined pipeline structure.
+
+Another example pipeline structure:
+crew1 >> [crew2, crew3] >> crew4
+
+This represents a pipeline with three stages:
+1. A sequential stage (crew1)
+2. A parallel stage with two branches (crew2 and crew3 executing concurrently)
+3. Another sequential stage (crew4)
+
+Each input creates its own run, flowing through all stages of the pipeline.
+Multiple runs can be processed concurrently, each following the defined pipeline structure.
+"""
+
+
 class Pipeline(BaseModel):
     stages: List[Union[Crew, List[Crew]]] = Field(
         ..., description="List of crews representing stages to be executed in sequence"