Python small & snytax issue [duplicate]

This question already has an answer here:

• Where are the ampersand and vertical bar characters used in Python? 3 answers

I just a have a quick question, i wasnt able to find a direct questions online. I have received some which contains this line:

'list1_new = sorted([sorted(list(s)) for s in list1c if s & set(list3)])'

I do not understand how the single & works here. If u wish I can upload whole code. Thank you