Check engine light is on

You have a trouble code,to get the code push in and hold speedo reset button and turn ignition on speedo will read diag. release button and push again to see the code,make sure you write them down then clear them out by pressing and holding the button.Then after you record them and erase them turn ignition off. then turn ignition on again and off then check the speedo again and if any of the same codes come back it is a current trouble code

I also need to know what the code means before clearing it.