What did the salt do in this experiment?

Question

In a lab experiment, a made ice cream by putting ice and salt in a gallon sized bag then inside that bag i placed a closed quart sized bag filled with milk and sugar. I shook it up for 12 minutes until it formed ice cream. Why did I add the salt to the ice and what did it do? Also, people put salt on the ice in the winter. How does this relate to the experiment above?

Answer 1

Salt lowers the freezing point of the ice.

Answer 2

salt lowers the freezing point of water so the ice melts. When the ice melts, it absorbs heat and makes the ice cream mixture cool faster than the mixture would without salt.