: The .rar extension stands for Roshal Archive . It is a proprietary format used to bundle multiple files into a single, smaller package to save storage space and make sharing easier.

: The official software for creating and opening these files.

Because Windows and macOS do not always support .rar files natively, you will need a third-party "unarchiver" or "extractor":

: Based on the name "Knowledge," it most likely contains documents, PDFs, videos, or course materials related to a specific subject, training module, or database. How to Access the Contents

The filename suggests it is part of a numbered series (e.g., "04") within a larger collection of data.