Apple today released macOS Catalina 10.15.4, the fourth update to the macOS Catalina operating system that was released in October. macOS Catalina 10.15.4 comes a couple of months after the release of macOS Catalina 10.15.3.
macOS Catalina 10.15.4 can be downloaded from the Mac App Store for free using the Update feature in the System Preferences app.
The macOS Catalina 10.15.4 update introduces Screen Time Communication Limits, a feature that was first brought to the iPhone in the iOS 13.3 update. Communication Limits allow parents to put limits on who children can contact through FaceTime, Phone, Messages, and iCloud Contacts.
Read more at MacRumors.com