<ul>
<li>after creating a file and doing <code>ls -ltr</code>, it has -rw-r--r--.
</li>
<li>after doing chmod +777 test.txt, it has -rwxrwxrwx.
</li>
</ul>
The file permissions are given to a particular user, group or owner, which has read permission where a certain user can read the file or not, write permission where a certain user can write the file or not and execute permission where a certain user can execute the file. Each of the three permissions is assigned to three defined categories of users.
The three commands for file permissions are:-
<ol>
<li>chmod -used to change the permissions of the file or directory.
</li>
<li>chown -used to change the ownership of the file or directory.
</li>
<li>chgrp -used to change the permission of a file or directory.
</li>
</ol>

* after creating a file and doing `ls -ltr`, it has -rw-r--r--.
    
* after doing chmod +777 test.txt, it has -rwxrwxrwx.
    

The file permissions are given to a particular user, group or owner, which has read permission where a certain user can read the file or not, write permission where a certain user can write the file or not and execute permission where a certain user can execute the file. Each of the three permissions is assigned to three defined categories of users.

The three commands for file permissions are:-

1. chmod -used to change the permissions of the file or directory.
    
2. chown -used to change the ownership of the file or directory.
    
3. chgrp -used to change the permission of a file or directory.

File Permissions and Access Control Lists