Legends in Isaldor
Half-Orcs are the product of the union of a human and an orc. Orcs are a race of extremely militant people who do not work the land or domesticate animals. Instead, they raid. Their rape-and-pillage culture are to kill all able warriors and leave the women pregnant with their own seed, slowly turning human settlements into their own by breeding out their enemies. These bastard children are their progeny.
Half-Orcs have slowly become a presence in the world of their own, however. They often choose to make settlements of their own. Half-orcs are somewhat more peaceful than orcs and are not opposed to simple farmstead living. As a necessity, they learn to fight, be it through martial or magical means.
Most other civilized races look down on half-orcs, but they have become a noticeable presence in the magical and clergy communities. They are also a got-to choice for mercenary companies, as young half-orcs are martially trained as children and take to the art of war almost as well as their full-blooded cousins.
Here’s the link ( http://www.d20pfsrd.com/races/core-races/half-orc ).