New to Building, what should be included in design?

We are about to building our first home and are excited to get started.

We have selected a company to design and build our house, they have a 2 part fee. Architecture design and Interior design/detailed joinery.

What we are wondering is what would be included in the interior design part of the fee? Would it include kitchen/laundry/bathroom design or is it just things like joinery in the WIR etc?

We are wondering if we just went with the architecture design would be get kitchen layouts etc or would that be considered interior design.

Thanks for your help, we will ask the design company but would like to go in somewhat informed so we don't look silly and they think they can walk all over us for the whole proces.

We are building for the first time too, and I was thinking about powerpoints, light switches etc. when it came to considering the build BUT...

The first meeting they just want to know about the structure... ceiling height, changes to walls, including built - ins, cavity doors, shower niches, extending the slab to include an alfesco area etc.

All other things powerpoints, light switches, kitchen and bathroom, laundry design refer to interiors.