Debian on CDs/DVDs
https://www.debian.org/CDOfficial CD/DVD releases are signed so that you can verify they are authentic. Debian is available for different computer architectures - make sure you are getting images that match your computer! (Most people will need images for amd64, i.e. 64-bit PC-compatible systems.) Once you have created your own discs, you might be interested in the ...
Debian -- Live install images
https://www.debian.org/CD/liveInstaller: Starting from Debian 10 Buster, the live images contain the end-user-friendly Calamares Installer, a distribution-independent installer framework, as alternative to our well known Debian-Installer . Size: Each image is much smaller than the full set of DVD images, but larger than the network install media.