What do the Asch and Milgram experiment demonstrate?
Simply they were a series of studies that demonstrated the power of conformity in groups. (Asch) for Milgram it was Obedience.
The Experimenters that were led by Asch. They would say something (Example, saying X line was bigger than Y line) when in actuality that was false. Then the participant would agree with them although they knew it to be false, thus the conformed to the group.
For Milgram the experiment showed that roughly 60% of people would carry on shocking a person when urged on by Milgran (Or whomever the person in authority was) due to obedience. Pretty much that humans can carry out unacceptable acts in the name of obedience.