Actualization is the achievement of goals and ambitions. Most of us have goals, ambitions, and desires in the pursuit of the improvement of our life situations. Actualization, or self-actualization, is the culmination of personal goals set and achieved.
For instance, a successful high school athlete may aspire to a career in professional sports. Through careful training and practice they may play sports for a large college or university. After playing well there and continuing to gain strength and skills (and publicity) for their sport this may lead to a contract with a professional sports team. If all of these steps are followed successfully a person might be considered to have met "actualization" of their athletic goals.