An inversion is:

When a record with key value greater than the current record's key appears before it in the array
  • A swap
  • A type of sort

We have not used "inversion" to refer to a type of sort.

While "inversions" are related to swaps (since ultimately a swap is needed to undo an inversion), it is not a swap.

Inversion refers to an instance of a record being out of order.