How many periods in world cup soccer?

There are two 45 minute periods in regulation, with upto 10 minutes injury time in each period (if needed). There is also extra time (15 mins each half) if it is a draw at the end of the match. There is also penalties after extra time. In some matches there is golden goal which is when you need to score a goal to win. If penalties are a draw the is sudden death when you have to score a penalty to win.

So in total there are 7 periods (not including injury time).

Complicated, isn't it?