Do not confuse the “updater” (small delta update) with the full “installer” (8 GB). The keyword typically refers to the full installation package that includes all updates up to 10.15.7.
If your Mac is older, you cannot run Catalina. Consider using a patcher tool like (unsupported, use at your own risk). macos catalina 10157 installer upd
Below it, a small terminal prompt blinked: Do not confuse the “updater” (small delta update)
If you need the complete installer (roughly 8GB–12GB) for a fresh installation or to create a bootable USB drive: Via App Store macos catalina 10157 installer upd
67 GB. Other. The gray ghost.
Apple distributes macOS installers in several forms: