> For the complete documentation index, see [llms.txt](https://docs.etiq.ai/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.etiq.ai/core-concepts.md).

# Core Concepts

### Lineage Graph

The lineage graph is the derived graph showing relationships between functions and lineage objects. It is based on both static analysis and runtime tracing. 

The default format is `dot`. Use `json` when another program or agent needs to consume the graph output.

### Lineage Object Nodes

Lineage object nodes are the common concept for objects captured by Etiq and represented in the lineage graph. Today this includes dataset/dataframe lineage objects and model lineage objects. The lineage object concept is intentionally broader because Etiq will support more object types over time.

#### Dataset Lineage Objects

Dataset lineage objects are dataframe-like objects captured during the run. 

#### Model Lineage Objects

Model lineage objects are model states captured during the run. 

#### Agent Lineage Objects

Agent lineage objects are agent states captured during the run. 

#### Unstructured Lineage Objects

Unstructured lineage objects are any states captured which don't fit into the above categories, such as strings or other arbitrary types.

### Code Nodes And Source

Each captured state stores a source node. The node points back to the code Etiq associated with that captured object.

Use the node when you need source-level evidence, such as:

* the code snippet for a captured object
* whether the object was captured at module level or inside a function
* the scope that contains the captured object

Example captured state:

```python
{
    "state_type": "DataframeState",
    "names": {"adf"},
    "line_no": 4,
    "value_type": "DataFrame",
    "node_type": "FunctionDef",
    "node_source": """
def add_one(adf):
    new_df = adf + 1
    return new_df
""",
    "scope_type": "FunctionDef",
    "scope_repr_first_line": "FunctionDef(",
}
```