Question on Mobile and Desktop Keywords

Sorry if this has been asked before but I tend to watch my traffic and keywords so to cut to the chase why am I showing a difference between Mobile and Desktop keyword numbers . Then my next question is if I am working on increasing my keyword count ranking 1 to 20 , how do I control or even can I where that effort goes to Mobile or Desktop? Would or could the difference be due to my social media ?

Wow, no one knows ? Was hoping for a little insight after seeing on my SEMrush Organic Search Positions panel that I had 8% more keywords on mobile than on desktop.