The Helvetica Neue Condensed is a narrower version of the Helvetica Neue. There is not much visible difference between the Helvetica Condensed and the Helvetica Neue Condensed except to a very discerning eye like that of a graphic designer.
In spite of this, the Helvetica Neue font is widely used in advertising copy, signage and graphic design where a font that does not have a message of its own is needed. The Helvetica Neue Condensed Bold is a darker version of the Neue Condensed and can be used effectively to highlight and emphasize certain points in an advertising copy or even personal communication.
You may also want to see: Free Helvetica Font: Helvetica Neue Bold