There is a general answer to this which is that it depends on the amount of material used – the g-string has far less material compared to a thong and jockstrap. However, there are other differences too.
Mens jockstraps have a front pouch to provide support and sometimes protection and/or lift. There is no side material, allowing the legs to move easily and hence a jockstrap makes a good option for wearing during sporting activity. The front pouch is joined to the back with jock straps, usually one around each buttock and usually elasticated. The lack of back material allows for maximum ventilation which again makes this style ideal for wearing during sports. A jockstrap will have an elasticated waistband, similar to a brief or boxer, holding everything in place.
Did you know? – the jockstraps was originally designed to be worn by bicycle couriers (who were known as ‘jocks’). The design allowed them to move their legs more easily when on the bicycle.
Pictured: PUMP! Fever Jockstrap
Mens G-strings have the least amount of material. They have a front pouch like a jockstrap but where a jockstrap has an elasticated waistband, the g-string has a piece of string that replaces the waistband. The jockstrap has straps around each leg whereas a g-string has nothing around the legs. The front pouch is held in place by a piece of string that joins from the bottom of the front pouch, runs underneath you, up the butt crack and joins to the back of the waistband string. So the pouch on a jockstrap is held in place with leg straps whereas the pouch on a g-string is held in place with a piece of string running down the butt crack rather than the legs.
Pictured: Andrew Christian Almost Naked G-String
Mens thongs are not really that different to g-strings. However, there is a subtle difference at the back of the product where there is a small piece of material inserted into the garment at the top of the thong. There is no real purpose to this, it’s just an aesthetic preference. The front pouch is again held to the back waistband with a piece of material running down the butt crack, rather than around the legs like a jockstrap. This may be preferable for guys who find the elasticated straps on a jockstrap to be tight and uncomfortable. A thong is also more likely to have an elasticated waistband like a brief or boxer, compared to a g-string being more likely to have a piece of string as a replacement waistband.
Pictured: Timoteo Booty Thong and Andrew Christian Almost Naked Thong