Hiding website directories from Johnnie Hacker using a .htaccess file

OK, here's the situation.
You're creating a website.
You want a directory called say 'classes'.
You need to access stuff contained in 'classes', but you don't want a user of your site to access the 'classes' directory through something like this http://www.yoursite.com/classes/
I'm assuming you've shown the good sense to use the apache web server here and that you haven't fallen foul of the Microsoft marketing machine or foolishly believed that you get what you pay for. That said, there are some good web servers other than apache.
I digress. Anyway, here is how to do it.


Go into the directory you wish to deny access to.
Create a file called .htaccess
Add a single line to the file namely:
deny from all
Save the file and restart apache.


If for some reason this doesn't work, it may be the way your apache server is set up.
Look for a file such as:
/etc/apache2/sites-available/default
That's if you're using a proper operating system. Goodness knows what it would be if you were using Windows.
In here you will see a few lines which look like this:

<Directory /var/www/>
Options Indexes FollowSymLinks MultiViews
AllowOverride None
Order allow,deny
allow from all
</Directory>
Change the line which says 'AllowOverride None' to 'AllowOverride All'.
Now restart apache again.

You can now add similar .htaccess files to any directories you want to control.