Executive presence refers to how others perceive and evaluate you based on factors like self-awareness, composure, and communication skills. It has offline and online components. Offline aspects include speaking ability, body language, and time management. Online involves using social media like Twitter, LinkedIn, and blogs effectively. Developing executive presence involves presenting yourself professionally, communicating well, seeking feedback, and using emotional intelligence. Tools like Buffer and About.me can enhance one's online presence, while having clear goals and admitting mistakes builds presence for CEOs.