Referring to the following wiki text derived from the http://wiki.apache.org/solr/Suggester.
"A common need in search applications is suggesting query terms or phrases based on incomplete user input. These completions may come from a dictionary that is based upon the main index or upon any other arbitrary dictionary. It's often useful to be able to provide only top-N suggestions, either ranked alphabetically or according to their usefulness for an average user (e.g. popularity, or the number of returned results)."
How the Solr knows which searched terms are more popular?
