Dynamics are important in order to create space and controling of your mixes. Watch the below video to get a basic understanding of how dynamics work.

This overview introduces dynamic processors, explores how they work, and how they manipulate audio files. Watch more at http://www.lynda.com/Logic-Pro-tutorials/Foundations-of-Audio-Compression-and-Dynamic-Processing/85998-2.html?utm_medium=viral&utm_source=youtube&utm_campaign=videoupload-85998-0104 This specific tutorial is just a single movie from chapter one of the Foundations of Audio: Compression and Dynamic Processing course presented by lynda.com author Brian Lee White.