Yeah, John Connor is a human...he just has a very messed up life.
Basically the future is a place where robots(built by humans of course) are trying to terminate humans (thus the Terminator movie name, and the name of the robots). At the end of the third movie they release nuclear missiles to destory all the humans, but a bunch survive. A guy named John sends back Reese to protect his (John's) mother, but it turns out Reese and Sarah (Johns mother) fall in love, so Reese is actually John's father. How this makes sense originally is not making sense, cause Reese would never have gone back in time if John had never ordered him to, and John would never have been born if Reese had never gone in time
so you see the predicament... only problem is that the timelines keep changing, where Judgement Day (the day the nuclear missiles hit every big city in the world) keeps happening on different days, on different years. Sometimes the humans win, sometimes the robots win, but they keep going back in time and changing it even more.
But yes, John is definately human.
If you want to find out more, wait for the fourth movie, coming out next summer. Arnold won't be playing the terminator though, so it won't be like the older ones. --- What, he wants you to have a broke leg, with sparkly white teeth? Will your sparkly whites distract people from your leg? freestyle313
Spartan-117 is a human, one kidnapped as a child by an intelligence division of the military for a program to create a spec op team that would control all the rioting, rebelling, pirating, etc that was getting very problematic at the time. That answers the question, but to detail why he's such the icon and his humanity is questioned, let's look at that program (unveiled during use in the covenant war to help morale)
The spartan project had to slim it's scope down to 75 child candidates, so already these are exceptional people. The children were trained immediately after their capture, no doubt carefully and with a heavy budget, so now they're people drilled into perfection. While the MC in the games can't show it, another strength was the group had kind of coordination gained from spending a lifetime of training together.
They were "made" into weapons in a more literal sense as well. At age 14 they were subjected to a cocktail of dangerous bio mods (altering their skeletal, muscular, nervous systems, etc) that cut their numbers in half.
To explain the suit, MJOLNIR, it turned out the Mark IV (the first model considered practical for the field) was so responsive that normal nervous systems weren't compatible, and only the spartans had the wiring (and strength/speed) to use them safely.
So it's a suit, on and off and not actually part of his body. It does make him all the more deadly, but imo the main function is so he's not so squishy. The tiny fusion reactor in Mk IV made it possible to use shielding on the Mk V.
It's my own fault I find it interesting, my roommate had the first three books. You don't need them though, all this junk is on the halopedia or whatever the halo wiki is called. --- "Ever squish your face on a window? Looks funny. Ever got stuck?" ~Falos