Alright anon let me help you out.
These are controls that your joints are parented to. The reason we use these is so we don't have to put keyframes on the actual joints because that would be very limited and causes problems.
1. These round circle controls are pretty straight forward most of the time. They control the body part that they surround. That's also why they are shaped that way.
2. This is the elbow vector. The elbow always points towards where this control is.
3. Probably the main body control, it's shaped differently to be easily distinguishable from the other controls
4. This is the heel control, it's a control that allows you to raise your heel while the foot actually stays in place. This is not a crucial control but generally makes your life easier because you don't have to counter animate the foot position.
5. this is the main foot control, if you move this one you also move the heel and toe controls.
6.This is the Global control. This control is parent over all other controls and is used to conveniently position and scale your rig in the world. You don't use this for animating, unless you work on games with stationary animation.
7. These are the knee vectors, the knees will always point towards where these are located.>>525849
It can be moved, scaled and rotated and all other controls will follow. It's to conveniently place your character in the scene before you start animating. You don't put animation on this control.
Any more questions?