For some time, i have used DD images at work to quickly transfer a linux image to a new harddrive in case the old one broke. It works great, no complains.
But, i needed to get a file from the image a couple of days ago, and was just about to go grab one of the drives and connect it to my computer to get it that way. However, i tried opening the image file as an archive with 7zip, and to my surprise, it actually worked!
Now is where i get a little confused. I know Windows 10 cant mount an EXT3 formatted drive, so how come 7zip can? I tried to look around, and i stumbled upon this answer, saying 7zip needs to support the filesystem. So, is it because it directly supports EXT3, like it does FAT, or is DD images written in a way where filesystems doesnt matter to 7zip when opening said image?
The reason i am questioning the linked answer is because, to my knowledge anyways, there is no stable program to mount an EXT3 harddrive in Windows 10. I know Ex2Fsd exists, but i have bad experience using said software (corruption, mostly), and so does a lot of other users i have read reviews from.
So, to recap: How can 7zip read an EXT3 DD image? Is it because there is no filesystem in such images, or is 7zip just more cleverly coded than other EXT3 compatible software for Windows 10?