Different cultures have developed varying relationships and language that help us to think about the subject. Fortunately, English actually has a number of terms that are used quite commonly to help point out the phenomena. Ego can often be used as a synonym for self. However, that does not mean it encompasses our entire being. It can be more useful and easier to conceptualizing when thought of as a third party that happens to exist in the same brain space as the actively conscious mind. Looking at it this way makes it possible to develop an increasingly precise relationship with it over time. (see "Looking at Layers: the Power of Perception)
Some of the English terms that attempt to point to this thing called ego are "self-control", "self-awareness" "acting selfishly" and even the phrase, "get over your self". Thefreedictionary.com gives this definition which seems to sum up the concept nicely. "egotism - the practice of thought, speech, and conduct expressing high self-regard or self-exaltation, usually without skepticism or humility." A commonly used visual metaphor is that of an angel and devil on each shoulder. In this metaphor, the ego voice (devil) attempts to convince a person to act selfishly, even at the expense of others. The higher self (angel) advises a person on what would be better considering everyone's point of view. Lastly the person in the middle, actually making the decision and taking action, is us.
Now one may be thinking, "Ego and instinct got us to this point. It has ensured the survival of the human race and probably all other species leading up to this point, so why go and turn our backs on it now?" That is certainly true that it has gotten us here. If we never gave a thought to it, people would likely go on surviving in some manner. However, for anyone interested in working towards precision, understanding this concept can play a critical role in helping one get there more quickly. One reason for this is because ego type, "natural", urges are generally very short sited. While they may help us survive now, it gives little thought to others or even to our own being in the long run. Ego thirsts to be satisfied quickly. It loves instant gratification. Each individual's ego wants something in the present to satisfy itself, but often it is so short sited that it hinders its own long term progress. While its' existence helps the continuation of people as a whole, it does not ensure the healthiest, longest, nor happiest life for the individual it inhabits.
For example, let's imagine being at a buffet. It's been my experience that even when I'm completely full and in no need of anything else, historically, I have continued consuming to the point of discomfort. In the moment, I just wanted to taste something more. (The desire to taste more, and repeatedly, is how the ego communicates to my conscious mind in order to get me to act.) Now my long term goals may consist of me getting in shape, or even wanting to feel good on the walk home. However, in satisfying my (ego's) very short term desires, I acted in a way that is actually working against the goals set forth by my higher cognitive self. If I want to have a precise relationship with my body and maintain it in shape, giving into this particular ego drive is causing me to act clumsily. (See "Clumsiness and Climbing Castles" for clarity on what I mean by clumsy)
In short, one way ego presents itself is in the desire to indulge in the here and now, without regarding what's to come. Indulging ego in this way can get in the way of realizing longer term goals that have been proposed by higher regions of the brain, a higher self even. This is not the only way that ego exists however. Clearly some people work long and hard for selfish means over a period of time. This too hinders the precision of society and even the world, but that must be saved for a future conversation. Thank so very much for joining me. As always, feel free to send me a message with any thoughts, critiques, or questions that may help clarify these posts. Until then, have a good one!