Q. What is the difference between a shortcode and locator layout settings?

A.    A shortcode is a WordPress-specific code that lets you do nifty things with very little effort.  Shortcodes can embed files or create objects that would normally require lots of complicated, ugly code in just one line.   In other words, a Shortcode = shortcut.

Layout settings  with  Store Locator Plus use a combination of shortcodes , html, and css and how they will appear is dependent on both the Store Locator plugin style you select and your theme.  If you have the Experience add-on you can add your own css , change the layouts for the  search, results, and map info bubble that appear on your locator page.  The span tag is used to group inline-elements in a document.  The <span> tag provides no visual change by itself.  The <span> tag provides a way to add a hook to a part of a text or a part of a document.