The controversy around "Sanctuary"

Hello everyone. When picking up my boys from their school bus stop yesterday they were accompanied by teachers handing out flyers titled “What to Do If ICE Comes to Your Door”, informing parents that it has been reported that ICE agents and border patrol are in Austin questioning people. I am not foreign born and neither are my children but even so this is extremely alarming. Every parent I know wants a great life for their children and a lot want their children to have a better life then what they had. For some people this means fleeing their country. Unfortunately for those people becoming legal residents of another country is not easy. With everything going on today I keep hearing the term sanctuary being used. Senate Bill 4 which focuses on drastically affecting funding for “sanctuary cities” recently passed the senate and is moving on to the House. Because of this I think its very important for Austin's residence to understand whats going on in our city. What does sanctuary really mean? Is Austin a “sanctuary city” and if so what is our city doing to follow through as a “sanctuary city”? I found an article titled “Sanctuary cities and the ways we fight for human rights” which helped me get a better understanding of where our city stands on these questions and all the controversy around it.