VSSE,
I think that everyone did a great job answering your question.
Check out a website like
www.midwayusa.com or
www.natchezss.com and look up speedloaders or speed strips.
www.dillonprecision.com sells some safariland speed loaders and bianchi speed strips.
Speed loaders hold 6-8 rounds in a holder so that you can load a double action revolver quicker by putting all of the ammunition into the cylinder at the same time.
HKS speed loaders by operating a knob. you put the rounds into the holes on the front of the speed loader, then turn the knob on the back. The rounds are held in place until you turn the knob in the opposite direction.
Safariland's Comp II and Comp I, you put the bullets in, press the whole system forward on a hard surface and turn the knob on the back. WHen you put the speed loader and cartridges into the cylinder, you keep pushing the speed loader against the back of the cyldinder. This causes a spring to be released and the bullets are released into the cylinder.
Speed strips are a piece of rubber that holds the rim of the case and you just put the bullet into the cylinder and pull the speed strip off of it. You load one cylinder at a time. These are typically easier to conceal. I haven't used them.
I use safariland comp II speed loaders more often than my HKS style speed loaders. I find the Comp II slightly faster than the HKS style.
I hope that helps for you.
-Jim