What is the basic difference between the electronic configuration of transition and inner transition elements?

Explanation

Transition elements have general electronic configuration : `(n-1) d^(1 - 10) ns^(1 or 2)` while inner transition elements have the general electronic configuration `(n - 2) f^(1-14) (n - 1)d^(0-1) ns^(0-2)` . Thus, in transition elements the last electron enters d orbital of penultimate (n-1) shell while in inner transition elements the last electron enters the antipenultimate (n - 2) shell.