Cisco Qos IP PREC/DSCP and Queing methods FIFO

i,
   I have just started studying cisco qos and just want to make sure i am understanding correctly dscp,ip precendence and queing methods. SO we mark traffic with whichever method cos,dscp,ip prec. These relate to priority so for example
ip precendence  5 is this top priority traffic like voice. When this traffic comes in marked to the router interfaces for quieing the router interface needs to support a priority queing method to use these markings??.

So for example if i am using fifo as my quieing no matter if 2 packets arrive 1 with ip precedence of 3 and another with ip precedence of 5 that it will be down to whichever arrived first so this quieing method is not ip precedence/dscp/cos aware and will not take into account these marking. So there is no point in using these markings unless you use queing that is aware of priority like low latency queing.

Is this correct or am i missing something.

Thks

Eoghan