Stop words are words that are ignored by the Oracle Commerce MDEX Engine when the words are part of a keyword search. Typically, common words (like "the", "a", "as", etc.) are included in a stop word list and also terms that are very common in your data set.

For example, if your data set consists of lists of books, you might want to add the word "book" itself to the stop word list, because a search on that word would return an impractically large set of records. In addition, a stop word list can include the extraneous words contained in a typical question, allowing the query to focus on what the application user is really searching for.