Technically, a Z64 file represents the ROM data in a specific "byte-swapped" order. When early N64 backup devices (like the Doctor V64) read cartridges, they would store the data in a Big Endian format. Without getting too bogged down in computer science, this refers to the order in which the bytes of data are arranged. Because the N64 architecture utilizes this specific order, .z64 became a standard for emulators that prioritized accuracy to the original hardware.
You can use standard ISO creation tools to "wrap" the .z64 file into a disc image. This doesn't change the game data; it just puts the file inside a virtual disc. z64 to iso
Converting (Nintendo 64) files to is generally unnecessary for standard emulation because they are entirely different storage formats for different generations of hardware. format is a of a cartridge-based game, while disk image Technically, a Z64 file represents the ROM data