What is a Concordance?
An alphabetical index of the principal words in a book or the works of an author with their immediate contexts
--Merriam Webster Online Dictionary
Therefore a Bible Concordance focuses on finding words mentioned in the Bible.
Holman concise topical concordance : an easy to use alphabetical reference covering hundreds of topics.
The new Strong's expanded exhaustive concordance of the Bible by 
Nelson's Foundational Bible Concordance by
Nelson's Foundational Bible Concordance is prepared with immediacy, simplicity, thoroughness, and accuracy in mind. Every passage of scripture can be located quickly and with ease. The most helpful tools have been included to aid in pronunciation, distinguishing multiple persons or places, and to understand actual meaning. Nelson's Foundational Bible Concordance includes the most likely places for the user to find every verse in the Bible. By eliminating common and non-distinctive words, references to more distinctive words within a given verse are easily located. Features include: An easy-to-use method for locating scripture passages quickly Tools to aid in pronunciation, differentiation between multiple persons with the same name, and understanding of the actual meaning In addition to thefull Concordance materials, the eBook version of Nelson's Foundational Bible Concordance also contains an appendixof the full text of the King James Version Bible. All verse references in theConcordance are linked to that verse in the Bible so that you can easilynavigate between the Concordance and Bible text.