Hi Lee and Hyder -
Per Lee's suggestion, I just ran a sample report and it seems like the answer to my question is - OR;
I have 2 segments, segment 1 - excludes internal IP addresses; segment 2 - excludes internal user emails;. The report that I want is a list of users that don't have internal IP address OR do not have internal emails. That is the result that I got. Can you please verify that same happens when you run a report in data warehouse? Thanks! Remember: I am building the report using tools ---> Data warehouse and adding both those segments from the available segments.