Activation Complex vs Transition State

[Jessica Luong 3K]

Can someone explain to me the difference between an activation complex and a transition state?

[Amanda Bueno-Kling]

The activated complex is "an arrangement of the two molecules that can either go on to form products or fall apart again into the unchanged reactants." (From the textbook, page 628)
"In the transition state theory of reaction rates, it is supposed that the potential energy (the energy due to position) increases as the reactant molecules approach each other and form an activated complex, then reaches a maximum at the transition state."
(From the textbook, page 628)
So the activated complex should be all possible intermediate states where the molecules can go to either products or reactants, but transition state should be the intermediate state with the highest potential energy.
The transition state and activation complex are shown on the attached photo since I find a visual representation helps.