rea.</p>

    <h3>Block</h3>

    <p>A block is small area of 512 bytes on a hard drive, and it is also part of
linked list representing a file or a directory.</p>

    <p>The first 4 bytes of a block is the address of the next block on the list and
the rest of block is the data stored in the block.</p>

    <p>Structure:</p>

    <pre><code> 0
 0 1 2 3 4 5 6      n
+-+-+-+-+-+-+-+ // +-+
| addr  | data       |
+-+-+-+-+-+-+-+ // +-+

n = 512
</code></pre>

    <h3>Superblock</h3>

    <pre><code> 0        