I don't imagine that this is the same thing... Cortex (chip architecture) doesn't have much to do with Accounting so for those to exist in the same context, I believe the employer to be asking about a similar accounting type of program or system.
Best advice (IMHO) is to be honest about your experience with the systems. If asked in an interview what experience you have with Cortex, be honest and say something like "The only time I've heard of the term Cortex was in reference to a processor architecture, so I believe you may be asking about something I'm not familiar with, what is Cortex?" and put the question back in their court. When they explain, you can then have a prepared response already of "Sounds interesting, I would love to learn..." and so on.
Humans are the only creatures that won't live up to the their potential. Give everything your all. When you die, die on E.
So I ask you, what do you intend to do now?