You really should know the difference between the type of aircraft you could fly, espcially the difference between boeing and airbus.
You would enter the scheme and be flying in around 2 years so the planes around today and are the ones you will be flying when you finish.
Things such as Boeing Airbus differences are general knowledge within the aviation industry so you should really know at least a little about it.
Also for those guys who were talking about application age a few posts back - I'm out in NZ with CTC at the moment and two of the guys on our CP are 19 so applying young needn't be a problem. That said I think the average is around mid 20s with most people I think having a degree.