Navigation (Nav) and Communication (Comm) radio receivers and transceivers are available as separate, individual radios or as a combined Nav/Comm unit.
A Nav/Comm unit is sometimes more economical in price than the 2 separate Nav and Comm radios and usually requires less panel space.
Obviously, one disadvantage to the combined Nav/Comm unit is in the case of unit failure you lose both nav and comm functions since the entire unit is removed.
KN-53 Nav:
KY-196A Comm:
KX-155 Nav/Comm: