With that, I'm basically saying is that, here, "full time" isn't necessarily 40 hours a week. It could be 20 hours a week. There's an overlap between full time and part time. I'm also wondering what category an on-call worker would be under or, quite simply, in this case, someone who replaces someone else for a long period, such as for a maternity leave.
The difference between "full time" and "part time" doesn't seem clear to me. Could you please clarify that for me? That's all I'm asking.