Is profit margin the same as net profit margin?
Profit margin is profit after the cost of sales. If you review an income statement, you will see revenue, and then typically a data field called “cost of selling goods”. Revenue - Cost of sales is profit margin. 

Net profit margin is Revenue - all expenses. So this includes taxes, interest expense, administrative expenses, and ALL expenses. An easy way to remember this is that profit margin is simply revenue - the cost of selling products, and net profit margin is revenue - ALL costs.