Making one track volume lower than another


I am a newbie and my question is pretty basic.

I have two tracks. One is a speeck (voice memo) and the other is simple music. Currently, both are playing with the same volume. I wish to make the music track go with a lower volume as a background music when the speech /voice is going on. How do it attain this?

Thanks in Advance!

You can use the Envelope Tool:

There is also an automated effect that you might be able to use, called “Auto Duck”: