At home there are usually a lot of devices using the internet. Unwanted advertisments Unerwünschte Werbung kann man mit diversen Browserplugins in einem can be suppressed with browser plugins but this requires to install a pugin on every device - multiple tablets, multiple smartphones, multiple laptops and multiple desktops.
A tiny Raspberry (e.g. Raspberry Pi 1) can be used to install Pi-hole which filters by using a blacklist unwanted advertisment for everybody located in the local net. Just install Raspbian (Stretch as of now) on a 4 GB SD card and follow the instructions available on github.
In order to use pi-hole all the clients have to use the Raspberry pi-hole IP address as their DNS resolver. If you have a router which allows to define the DNS server to announce to all local clients it's much easier. Just define the pi-hole IP address as the DNS server to announce and then all local clients will use this DNS and block any advertisment.
If you want to encrypt your DNS queries so your provider cannot see which DNS queries your clients execute install DNSCrypt in addition on your Raspberry. You also can use DoH (DNS over HTTPS) to encrypt DNS queries. See here for detailed instructions from PiHole development.