Download macOS Catalina 10.15.3 Combo Update
The macOS Catalina 10.15.3 update improves the stability, reliability, and security of your Mac, and is recommended for all users.
• Optimizes gamma handling of low gray levels on Pro Display XDR for SDR workflows when using macOS
• Improves multi-stream video editing performance for HEVC and H.264 encoded 4K video on the 16-inch MacBook Pro (2019)
For more detailed information about this update, please visit: https://support.apple.com/kb/HT210642
For detailed information about the security content of this update, please visit: https://support.apple.com/kb/HT201222