Is ext4 and xfs only for usage with internal file systems?

I am attempting to store some large files and I thought an encrypted ext4 partition would be excellent. However the GNOME Disk Utility appears to state ext4 as for internal disks and xfs only for Linux filesystems. Can I utilize them both safely with removable media? Is there one that is more utilitarian for this usage? What makes them different? _________________ Thank you so much for any information you can provide.