This is the modern version of the Acronis True Image backup format. It is designed for speed and incremental efficiency. However, it is proprietary , meaning you generally need Acronis software to read or extract it.
Most VM software (Hyper-V, VirtualBox) can boot directly from a VHD. convert tibx to iso exclusive
Converting TIBX to ISO: The Exclusive Guide to Image Migration This is the modern version of the Acronis