I see two types of electrical tape: one type is thin with a slick shiny side and adhesive on the other side (like common electrical tape), and the other type appears to be made of cloth or some such material and is thicker than the first type and doesn't seem to be as sticky. What's the difference and where should each type be used?

 

Sounds like your either talking about Duct Tape or Gaffer Tape. Neither are good for electrical stuff (due to the cloth embedded in them).

 

NPD (I believe that's where I saw it) advertises a non-adhesive tape that is supposed to be used for wrapping wires. If it's non-adhesive how does it stay on?

 

3M brand elect tape that comes in the plastic container is the best