Hey there- welcome to the forum!
I use a martingale on my Shiba bitch. Most people in Shibas reccommend that you walk them on a martingale because their uniquely "bullet-shaped" head allows them to back out of a collar only too easily. And once a Shiba has slipped it's collar....well, good luck catching her! (As a breed, Shibas are known to be absolutely HORRENDOUS when it comes to recall).
All it took was one nerve-racking experience with my first Shiba boy- and I bought a martingale the next day.
Suzanne- a martingale is very similar to a regular flat nylong buckle collar, except in this case it slips over the dog's head instead of buckling. It has an extra loop of material on which the d-ring is connected to that allows it to tighten slightly so that the animal can't "back out" of the collar.
Prong collars are metal training collars (vaguely similar to a choke chain) that have an even distribution of prongs all the way around. These apply even pressure on the dog's neck if it pulls. A lot of people use them with dogs that are difficult to control when walking.
I would advocate spending some more time training a dog to walk appropriately on lead than using a prong collar, which is more of a "band-aid" than a solution. I have seen some cases with rescue dogs that were completely out of control where the use of one was necessary. These were animals that were nearly impossible to walk, and a solution was needed *immediately.* I wouldn't want to walk a dog on a prong for any extended period of time, however.