File Permission on Linux

a) Fstab file explanation

ro = read only (cdrom)
rw = read write
nosuid = prevents set user identifier
noexec = no execution of file
noauto = mounted manually, not mounted at boot
users = all users can mount filesystem, by default only superuser can mount 
acl = access control list
usrquota = user quota
grpquota = group quota

b) Mount Command to show mounted devices

mount

c) Mount everything that is not defined as auto

mount -a

d) Mount devices

mount /dev/sda1 /media/yourdirectory

d) Mount devices with filesystem type, -t for type

mount -t ext4 /dev/sda1 /media/yourdirectory