What is 'ego' anyway?

In the last week, on more than one occasion, the word ego sprung into my conversations with people. This made me wonder, if I am an egoist? I decided to google what ego is and damn, I found too many results. The most sensible data I got about ego is right here in quotes - " A simple psychological definition of the ego is something like the "self-organizing principle," that all-important command center in the psyche that coordinates the different aspects of the self. And that command center must be in good working order for a human being to be able to function in the world with any reasonable degree of competency. The ego as self-organizing principle is neither positive nor negative; its function is mechanistic, and in that, it has no self nature. But there is another definition of ego— the ego in that definition has self nature. The human face of that ego is pride; is arrogant self-importance; is narcissistic self-infatuation; is the need to see oneself as being separate at all times, in all places, through all circumstances—and that ego is the unrelenting enemy of all that is truly wholesome in the human experience. "
This kind of answered my question. A lot of times, frankness and speaking your truth, comes as arrogance and egoism to a lot of people. My introspection gives me data which says that, per the above definition of ego, I am egoistic if the first definition of ego is considered right and I am not egoistic if the second definition of ego is considered right. I could try to make every person I know, understand that I am not really an egoist, but then whats the point? I am really not trying to prove any point here. All I really am trying to say is, if speaking out my mind is egoism, then yes, I am an egoist. Similarly, if being assertive is egoism, then yes, I am an egoist. If standing up for myself is egoism, then yes I am an egoist. If defending myself when others treat me like a piece of crap, then yes I am an egoist.
As humans, every single one of us is selfish. Afterall, that is why we are humans. Don't we remember, Darwin's theory? But sometimes, being focused and determined, is misinterpreted as being selfish. I believe that as long as you don't have an intent to ha
rm anyone emotionally, mentally and physically to achieve your goals, you are not to be called self centered.