Is the VirtualNes emulator allowed? Because I don't know if he is or not, I just want to know.

What is the difference between LRT and RTA? And why is the LRT time always (or almost) the same or less?

What is the difference between LRT and RTA? And why is the LRT time always (or almost) the same or less? I have doubts because when I uploaded my High-five% speedrun I thought it was 1:36 and in LRT it turned out to be 1:29 but, in my speedrun of death% by huggy the 2 strokes LRT and RTA were the same, which doesn't make sense to me, can someone tell me?