# Copybook Input The Copybook Input step reads binary data files that are mapped by a fixed-length COBOL copybook definition file. COBOL definition and binary files are used in IT scenarios that include data stored on mainframes. You can extract the binary data files and the definition files from the mainframe for data transformation and analysis, and avoid using mainframe cycles for complex data analysis tasks. **Note:** The Copybook Input step performs self-contained static extraction of the data in the binary format. If you only need to perform ETL metadata injection, use the [Read Metadata from Copybook](https://github.com/pentaho/documentation/blob/main/PDIA/10.2/PDI/Transformation%20steps/PDI%20transformation%20steps%20reference%20\(overview\)/Read%20metadata%20from%20Copybook=GUID-6DF7C90E-B8E6-4E70-9E49-EC9CACB1808F=3=en=.md) step. You are not required to use both copybook steps in the same transformation. For more information see [Copybooks in PDI](/pdia-data-integration/10.2-data-integration/advanced-topics-pentaho-data-integration-overview/copybook-steps-in-pdi-cp.md). --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.pentaho.com/pdia-data-integration/10.2-data-integration/pdi-transformation-steps-reference-overview/copybook-input-pdi-step.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.