what`s the meaning of primitive in "gradient descent primitive"?

Hi all,

I am reading the doc of spark (http://spark.apache.org/docs/0.9.0/mllib-guide.html#gradient-descent-primitive). I am trying to translate the doc into Chinese, and there it talks about gradient descent primitive, and but i am not quite sure what it mean by primitive?

I know gradient descent, but I am not sure what he is referring to by gradient descent primitive? does it mean the most basic form of gradient descent?

please enlighten me. thank you in advance.