Virtue ethics is an approach to ethics that goes back to Plato and Aristotle, and it is a theory that focuses more on what sort of a person we should be, unlike Kantian ethics and Utilitarianism.
Virtue (arête) is excellence in terms of human action, and virtues are character traits such as honesty, chastity, courage, and generosity. Virtue theorists believe that if we concentrate on being righteous people, the right actions will follow; in other words, the people with the right character tend to make the right decisions.
Virtue ethics can be broken into two parts: eudaimonia (the highest good a human can achieve), and the actual virtues (arête) with which we attain eudaimonia.
In book one of The Nicomacheon Ethics, Aristotle talks about how happiness seems to be the ultimate goal towards which all of us are acting. He believed that the key to happiness is the practice of virtue, because virtue is in accord with human reason. Aristotle stated that we can reach minor states of happiness through money, power, or fame, but eudaimonia (ultimate happiness) can only be reached though the practice of virtue.
There are two kinds of virtues that he recognises, intellectual and moral. He believed that if we only had one and not the other then we would not be capable of true virtue, and therefore would never achieve eudaimonia (ultimate happiness).
Aristotle also talks about human function in The Nicomacheon Ethics Book I, and he says that while we are all born with the capacity to be virtuous, being virtuous is a skill that we need to learn and practice to be good at. For example, being a good carpenter is just the same thing as successfully performing the functions in which being a good carpenter entails. Similarly, to be a good human is the same thing as effectively performing the functions in which being a human consists. Aristotle said that humans have a rational soul; the use of reason functions as the central principle for human action. Hence, he believed that being a good human — living a life of eudaimonia — consists of engaging in rational activity.
Aristotle reasoned out a set of virtues that will help a moral agent to be a successful member of society, and would bring them eudaimonia.
He emphasised the attainment of virtue and happiness through moderation in all things. 
There are twelve moral virtues that he created, and to workout the virtues that we should follow, Aristotle identified the mean, which stated that the virtue we should act accordingly to lies between two vices.
In other words, there are two ways in which humans might go wrong; there is always a vice of excess, and a vice of deficiency. Therefore, virtue is the mean point between these two vices; this is the doctrine of the mean.
For instance, Aristotle gives an example of the virtue of courage; cowardice (feeling too much fear) is the vice of deficiency, and rashness (feeling too little fear) is the vice of excess, so, courage is the ‘golden mean’ because the virtuous person is the one that is both appropriately afraid and yet also appropriately brave.
According to Aristotle, moral virtues can only be cultivated through habit/practice; he stated:
“we become just by performing just acts, temperate by performing temperate acts, brave by performing brave acts.”
What Aristotle means by this is that by repeating our behaviours until it becomes a habit, we form the basis of our morality. Our disposition is to do the right thing, as we perceive it.