This appears to refer to (used for BMW diagnostics, coding, and flashing with tools like ISTA, E-Sys, or ENET cable), where v.4.27.20 is a specific version.
Disclaimer: This article is for informational purposes only. Always comply with local laws and BMW’s terms of service. v42720 psdzdata lite download new
(flash firmware files) required for updating modules. This version is much larger (30GB+). Compatibility & Troubleshooting Version Mismatch This appears to refer to (used for BMW