What Is Inversion in General?

In general, inversion in science means a process of seeking the cause to a result with the latter on hand.  An opposite concept would be predicting the result from the given
cause and this is often referred as (forward) modeling.  An inversion process usually involves one or more of forward modeling steps in the course of examining possible
candidates of causes.  An inversion is called “unique” if there exists one and only solution, whereas “non-unique” if multiple solutions can exist.  It is called “linear” if the
cause-result relationship is linear as a small change in cause gives also a small change in result, whereas “non-linear” if a small change can give rise to a big change in
result.