What is contained in the /etc/fstab file?

The /etc/fstab file contains a table of file systems that should be automatically mounted at system startup or can be mounted manually using the mount command. It describes devices (e.g., disk partitions), mount points, file system types, mount options, and parameters such as access modes and error behavior.

Example of an /etc/fstab line:

/dev/sda1   /   ext4   defaults   0 1

Here:

• /dev/sda1 — device (disk partition)
• / — mount point (root file system)
• ext4 — file system type
• defaults — mount options
• 0 — dump utility (usually 0 or 1)
• 1 — fsck order at boot

Thus, /etc/fstab manages which file systems are connected and how.