The only difference is that the threshold is lower, that is, there are more highlights in the Ground texture than in the Water texture, that, to compensate, shine less brightly
its a solid, plastic encasing thats used to further protect your cards
Cards like Sword of the Chosen could tap to give a creature a temporary buff, but were never attached to that creature specifically
It is capable of many things, ranging from the acquisition of effects which certain cards only hold when they're Summoned in an specific way (a simple example would be Traptrix Dionaea, which has an at Normal Summon and a different at Special Summon effects), or avoidance of penalties for being Summoned in other ways, like the typical card that must be destroyed or returned to hand at the end of turn for being Special Summoned, or the high leveled mon that is at its strongest when Tribute Summoned