In UE5, what's the different between serveral IK system? like IK RIG/ CONTROL RIG , I am confused

[ATomCZ1]

I’m also lost in this a little bit, but here is already some discussion about this topic

Control rig vs ik rig

I’d like to know the difference between the two? From the outside, they look like they function the same, and I find ik rig easier to setup than control rig. Anyone has any idea as to why? Thanks,