Catalina is the last macOS version to support 32-bit applications. If you need legacy software, do not upgrade to Big Sur or newer.
Advanced users can download the installer via Terminal using: softwareupdate --fetch-full-installer --full-installer-version 10.15.7 . 2. Alternative Sources for DMG Files
Before clicking any download link, it is crucial to understand what a DMG file is. A file is a mountable disk image used in macOS. When you download a legitimate macOS Catalina 10.15.7.dmg , you are not downloading a live installer; rather, you are downloading a container that holds the Install macOS Catalina.app .
Here are a few options for the text, depending on how you intend to use it (e.g., for a website download button, a blog post, or a technical guide).
Apple typically provides the full installer as an file in your Applications folder rather than a direct DMG. However, you can use these official tools to fetch it: