Locus of control refers to the extent to which individuals believe that they can control events that affect them. Individuals with a high internal locus of control believe that events result primarily from their own behavior and actions. Those with a high external locus of control believe that powerful others, fate, or chance primarily determine events. Those with a high internal locus of control have better control of their behavior, tend to exhibit more political behaviors, and are more likely to attempt to influence other people than those with a high external locus of control; they are more likely to assume that their efforts will be successful. They are more active in seeking information and knowledge concerning their situation.
One's "locus" (Latin for "place" or "location") can either be internal (meaning the person believes that they control their life) or external (meaning they believe that their environment, some higher power, or other people control their decisions and their life).
I have a very high internal locus of control in the sense that I very much believe my life is in my own hands and only I can bring about things that I want and make headway in terms of bringing about change in my life as I see fit. I also tend to be highly disciplined and would say I'm in pretty good control of my behavior. However, I do not relate to the piece describing political behaviors, nor attempting to influence other people. Perhaps that's my introversion.
I do however recognize/believe more and more my lack of control over other people (people ultimately take charge of their own lives of their own volition, or disregard their own lives/responsibility) and most things outside of myself, so that is another reason I tend not to try to exert much influence over others - typically I don't see much point. I might provide input, if the other person seems receptive to it or is seeking it, but I don't push my views/influence on others.
I think there is certainly an element of chance in life, and I'll be the first to admit the chips don't always fall the way I hope they will. There is also much inherent in life that is absolutely out of my control - and there are ways others influence me or impact my life, so external people/things will always be a factor (obviously. When it comes to larger social institutions/laws/government, external crises/disasters, illness, other people, etc etc etc to the infinity). There will always be the unknown.
But by and large, even with outside unpredictability, for the most part I believe my life is what I choose to make of it, and my life is the result of each and every choice that I make.