Question about instances

I am trying to implement a component text/binary parser, and a lot of things are confusing for me. These are validated examples.

(component $C
  (type s32)
  (instance (export "inline" (type 0)))
)

What kind of component does the instance create? $C?

(component
  (type (component
    (import "x" (instance $I (export "f" (func))))
    (alias export $I "f" (func))
  ))
)

For me a type should contain only types or some descriptors, but it seems any mutable objects can be added a to (non-mutable?) type.

The most confusing part is how instances are connected? E.g. the (func (param "X" (list (list s32)))) is the import and export of two components, and the import side wants to call this function. What should happen? How this is represented in core module side? How the data is transferred?

Start with the component text/binary parser and the examples involving component, type, instance, import, export, alias, and core modules. Trace how instances connect across component boundaries and how values such as nested lists are represented and transferred; done means the issue's conceptual questions are answered clearly in the relevant specification documentation.