IP address

An IP address is a suite of numbers from 0 to 255, seperated by dots (for instance Every time you connect to the internet, you ISP (Internet Service Provider) assigns you a public IP address. This address is unique, and it can be used to access content on the device that has this address. In that case, the device is called a server.


DNS stands for Domain Name System. It is a service that is used by computers to connect to websites. When a computer tries to connect to example.org, it sends a request to a DNS server, which sends a response containing the IP address of example.org. The connection from the computer to example.org is now possible.

Hosts file

The hosts file is a file that is present on all operating systems. It acts like a DNS, but has a higher priority than the DNS. It can be used to redirect hosts (such as example.org) to custom IP addresses.


As the name suggests, a database is simply an efficient way to store data.

Filter list

A filter list is a text file, containing a list of domains (for instance example.com), that can be used by an ad-blocker to block all domains that are on it. Depending on the format, it is possible to also whitelist some domains inside a filter list. Whithout filter lists, ad blocking wouldn't be possible.


A rule is a way to tell an ad-blocker what to do about a specific domain. In fact, a filter list is a set of rules, that tells the ad-blocker which domains to block and which not to block.

Filter list format / syntax

The format (or syntax) of a filter list is simply a way to write rules inside the list so that the ad-blocker understands what to do with the specified hosts. Different ad-blockers use different formats. For instance, Adblock Plus uses an advanced syntax that allows to block hosts under certain conditions. This is not possible with others, such as AdAway or pi-hole, or TBlock. However, TBlock supports the most popular filter lists. It means the users should not have to worry about that.


A policy is the instruction a rule gives to the ad-blocker about a specific host. A policy can either be ALLOW, BLOCK or REDIRECT. If the policy is ALLOW, then the host is whitelisted. If the policy is BLOCK, the host is blocked, and if it is REDIRECT, the domain is redirected to the ip address specified in the rule.


In computing, a daemon is a program that runs in the background, performing invisible but yet important tasks for the daily user. Without daemons, it wouldn't be possible to have a graphical desktop.