Concur is simply compliance software which works with other booking software. That could be, for instance United.com.

Concur can check to make sure that a given traveler is complying with whatever rules the traveler's employer sets for that traveler, e.g., class of service, carrier, refundable, and so on.

Presumably, OP's employer has worked it out so that UA will provide all of the reporting which the employer needs.