Configuration file for the file system.
During the boot process, this file is accessed to see which partitions should be automatically mounted.
It is no longer necessary to list /proc in /etc/fstab. The boot system will always mount them.
If /proc is listed in your fstab, it is probably a remnant of an older installation and it can be removed.
To find the equivalent of /etc/fstab on Android, search:
# find / -type f -iname '*fstab*' 2>/dev/null