How do these differ?
You do not have to be part of a Distribution branched community to run Debian. These are built by the Debian community. Distribution communities come and go and with these you will not be left hanging with what to do when the branch suddenly disappears.
These are not your run of the mill minimal installs you find on Youtube. Some of these can be quite heavy as I have seen them as high as 5.9Gb in size. They are not for your old dusty laptop hiding in the corner. These installs are for production desktops/workstations that you would normally install something like Windows 10/11 on. The difference is that these are highly stable, usable platforms to perform work on.
How do I use these files?
The files here are complete ISO images, ready to use.
Once you have downloaded all the ISO images you want, you will typically need to write them to media, either writeable DVD or a USB stick.
Memory usage
Live images tend to be resource hungry by nature - they need to use memory to extract and store the compressed system as well as the memory that the running software would normally need. The minimum recommended RAM for using a desktop environment on a live image is 2 Gb. If you have a system with less memory, your system will not work well here. For a normal working system I highly recommend at least 16Gb of memory. This will yield a stable platform.