It is the present participle of the verb "range," which means:
* To extend over a particular area or period.
* To vary within certain limits.
* To move freely within a defined area.
So, "ranging" can be used in sentences like:
* "The prices of these items ranging from $10 to $50."
* "The wildlife in this park ranging from deer to bears."
* "His interests ranging from music to sports."