Just to elaborate on fehrke's accurate information
In your case Deny is applied first, allow second (Deny, Allow)
In this order Deny All is what it says on the tin all will be blocked. Unless seperate Allow rules are defined.
Aswell as localhost, you can use the following.
A (partial) domain-name
Example: Allow from apache.org
A full IP address
Example: Allow from 10.1.2.3
A partial IP address
Example: Allow from 10.1
A network/netmask pair
Example: Allow from 10.1.0.0/255.255.0.0
A network/nnn CIDR specification
Example: Allow from 10.1.0.0/16
E.g.
<Directory /portal/console>
Order Deny,Allow
Deny from all
Allow from 10.1.0.0/16
</Directory>
In other cases
You can reverse this idea to block select individuals (known trouble makers, departments, etc. Using:
<Directory /your/site>
Order Allow,Deny
Allow from all
Deny from some.abusive.host
</Directory>
Hope this helps to understand this particular area of apache httpd
Rob
Grumpy by name, helpful by nature