13.4 quotacheck (/etc/fstab vs /etc/mtab)

gowanby

I'm probably splitting hairs here the man pages for quotacheck says that -a checks /etc/mtab and not /etc/fstab. On my system (CentOS 7) /etc/mtab is linked to /proc/self/mounts. Are mtab and fstab somehow related via the mount command and can be used interchangeably?