Public speaking is the process or act of performing a speech to a live audience. Public speaking is commonly understood as formal, face-to-face, speaking of a single person to a group of listeners.
The truth is that public speaking is a skill. It can be learned. While some people may have more natural speaking ability than others, or a more pleasing voice, or are more charismatic—anyone who can speak can learn to be a better public speaker than they are right now. It just takes some know-how and some effort.