softwareupdate --fetch-full-installer --full-installer-version 10.15.7 Use code with caution.

While Catalina introduced major features like Sidecar (using an iPad as a second screen) and the splitting of iTunes into Music, Podcasts, and TV apps, the was primarily a stability release. It included:

This version includes critical security patches that protect against modern vulnerabilities. Where to Download the macOS Catalina DMG