Fstab files resides in /etc/fstab entries be like the following ones.
UUID=1172gfe1-3d7c-44g8-9ad5-0d0b6e0485dd /mnt/test xfs defaults 1 1
First field: has the info about the device name (/dev/sda) either as device name or UUID
You will get the UUID by running the following command
blkid /dev/sda
/dev/sda: PTUUID="d075f7ba-e9f6-483e-a7b3-8586e7ac147f" PTTYPE="gpt"
Second filed: has the info about the mount point which is a directory we need to create. ( /mnt/test )
Thrid field has the info about the file system type.
Like ext2,ext3,xfs,reiserfs,Swap,vfat,ntfs,ISO 9660 ,Auto
Fourth field has the info about the mount options. Mainly we use “defaults”.
auto and noauto -- options for how to mount the device on boot time
exec and noexec -- option for executing/excluding files residing in the device
user and nouser -- Options helps to sets a privillege of a user to mount device as well as restrict users (mainly in floppy device mounting)
ro and rw for read only/read write
sync and async How the copying of files to the filesystem done. async writes to filesystem during unmount
suid / nosuid permit/unpermit the operation suid and sguid
Defaults - normal default for Ext3 file systems is equivalent to rw,suid,dev,exec,auto,nouser,async(no acl support)
Fifth field has the info about the backup. Zero for excluding nonzero value for taking backups
Sixth field has the info about the fsck check. Zero for excluding it and non zero value for enabling. One used for the root partition for checking fsck