There're a lot of filesystem formats out there—some are more popular than others; some are used for very specific tasks; some are the darlings of certain operating systems; and others simply should have gone away years ago.
In the Windows world, we typically see NTFS, but FAT32, exFAT, and even FAT16 in some cases are still options.
More recently, Apple has dropped the ageing HFS+ and moved full-steam toward APFS as its filesystem of the future.
FreeBSD defaults to either ZFS (if you've got the RAM for it) or UFS (if you haven't).
OpenBSD—well, OpenBSD uses FFS, which is exactly as good as it sounds.
Linux is a whole other kettle of fish because, not only does it do all of the filesystems listed previously, to a greater or lesser degree, it also has hundreds of others to pick from...
