Personality development in itself is a very vast subject. It covers everything from your basic interpersonal skills to your outer behavioural pattern. It is a part of every body's life. If we understand the concept and try to implement it in our life, then nothing can stop you to achieve your goals. In short, Personality Development teaches you how to improve your personality.
It included; Your attitude, body language, stress, voice, motivation, confidence, dressing sense, group discussions, interviews, your fear etc. Improving your personality and overcoming your weaknesses help you in your existing job and also to get a new one.