This is a collection of domains that serve ads, ad related content, analytics, tracking, etc. I want to prevent my phone/laptop to make connections to these domains -- they do not serve anything useful for me.
Many of the popuplar lists out there -- like EasyList -- do a wonderful job of providing a central list of such domains. However, I realised that there were many obvious domains that were missed in EasyList. So, I started adding those on my own. I kept on adding these rules in many tools -- various adblocking extensions for browsers, VPNs for Mac, adblcoker VPNs for iOS, etc. Most of these lists was lost when I stopped using those tools or formatted my phone, laptop. When I start afresh, I was repeating the same process of finding these domains and block them. That's when I realise that I should put this in a common place and what's better than github to start with.
Do note that these domains are solely intended for my own use. There are many domains which may provide some useful behaviour to many users but not to me, so I prefer to block them. As with everything else out there, if you want to use this, do it at your own risk.