Larger than humans but smaller than trolls, the Orcs are the most powerful strain of the Savagefolk. The culture of the orcs lends itself to accepting the guy who can kick your ass as your leader, which allows them to be much more organized than their smaller relatives, even if they aren't as clever. The orcs live in tribes of a few hundred individuals, sometimes 'domesticating' Goblins and Trolls. There are only around twenty or so of such tribes in existence today, since they were nearly hunted to extinction centuries ago. With help from the cleverness of the goblins, which they have been able to organize and put to use, and the labor of the Trolls, the Orc society has developed a system of writing, ability to grow food, and willingness to trade and barter with humans.
Their culture is warlike and brutal. Your worth in life is derived only from your ability to provide for your tribe. If you can't contribute, then you don't deserve to be carried. If someone thinks you're getting useless, they'll pick a fight with you to see if you suck at fighting or not. If the elders think you suck at fighting, then once the fight is declared over with, they give the order to have you beaten to death. As you can imagine, 'elders' don't last very long, because the older, wiser ones are also not very likely to fight good.
Orcs can interbreed with humans. In all honesty, that probably most commonly happens when a male orc gets his hands on a human woman, to put it lightly. Their offspring have their own page: Half Savage
Orcs can interbreed with goblins. A female orc would not typically be attracted to something so small and unable to defend her and her children. A male orc might get seduced by a clever female goblin, but he would be shamed for it and viewed as taking advantage of someone smaller and weaker than him. An orc-goblin hybrid might look like a slightly smaller orc, but would still be called an orc, or a "weakling orc."
Orcs and can also interbreed with trolls but they view this as bestiality, big taboo. An orc-troll hybrid would still be called an orc, or "giant orc."