Q: what is jump ring
A: for connection purpose, it can connect two components. It can be opened or closed

Q: tools
A: jewelry pliers: chain nose pliers, bent chain nose pliers

Q: open
A: Always open a jump ring from front to back (bottom left) so that you can close it easily so the ends will meet (bottom right)
   Opening a jump ring from side to side is a big no-no (top left). It weakens the ring and makes it harder to close up nicely.

   When you close your ring, the ends should not be overlapping (top right) as this makes the ring vulnerable 
   to catching on things and pulling apart.