Let me try a little down under explanation
Single spinner diffs transfer drive from one wheel to another depending on weight etc so as you turn corners the inside side of the diff slips, drive transfers to the outside axle allowing it to catch up . When smoking the bags generally one side will slip & only one wheel will spin, hence the term single spinner.
Limited slip diffs, as the name implys limit the amount of slip to the axles to improve traction & drive out of corners, it's also handy for commercial vehicles. When frying the hides both tyres will generally turn at pretty much the same rate, giving more smoke & 2 black strips
If you jack the car under the diff & get a mate to firmly grab one tyre, you then try & turn the other, if you are fighting each other you've got an LSD. If your wheel turns & matey's is stationery you've got a single spinner.
Just to finish a locked diff does not allow for any slip between the axles which is why you see the tyres slipping and fighting each other when any vehicle with a locked diff is at low speed & changing direction. Great for drag racing 'cause traction is evenly applied to both wheels, not much good for a regularly driven street car unless you don't mind doing regular diff rebuilds.
Hope this helps
Cheers SoS
