I have a questions regarding t cells in reference to the screenshot attached

1.Do we have something called as (memory T cytotoxic cells ) , because as we know that the activation of Cd8+ and cd4+ T cells take place separately (after single negative maturation step in thymus) and we also know that after intraction with antigen they produce effector cd8 and effector cd4 cells along with the memory T cells (as showed in screenshot, but i never heard of the term 'memory cytotoxin T cells' ) why so ...do we only have momory T helper cells or both both of them exist(memory cytotoxin T cells and momory T helper cells)