If you found this file online, be cautious. Cracked or "repacked" versions of professional software in .rar format are common vectors for malware. Always ensure you are downloading software from official or verified sources.
While it looks like a simple utility file, here is why it might be considered "interesting" or important to someone: Illustrator 2019.rar
: The .rar extension means the contents are compressed to save space. You would need a utility like WinRAR or 7-Zip to "extract" the installer inside before you could use the software. If you found this file online, be cautious