You cannot open a RAR file with built-in Windows tools like you can with a ZIP file. You will need third-party software:

The official tool for creating and managing RAR files.

Large files can be broken into multiple parts (e.g., .r00, .r01) for easier uploading. 🛠️ How to Open 51853.rar

rar - ArchWiki

Only download archives from trusted forums, official support sites, or known developers.

Often includes a "recovery record" to fix the file if it gets slightly corrupted during download.

A RAR file (Roshal ARchive) is a proprietary format that compresses data more efficiently than standard ZIP files. Shrinks large folders to save disk space.