The df command, which stands for “disk filesystem”, shows a summary of the available and used disk space on your Linux system. With the -h option it shows the disk space in “human readable” form, which in this case means, it gives you the units along with the numbers. For example,
will output a table with four columns. The first column contains the file system path, which can be a reference to a hard disk or another storage device, or a file system connected through the network. The second column shows the capacity of that file system. The third column shows the available space, and the last column shows the path on which that file system is mounted. The mount point is the place in the directory tree where you can find and access the that file system.