Speaking collectively to audience large or small is public speaking. The first requisite for a good speaker is a good voice - neither too loud nor too low or inaudible, not harsh but sweet, and far-reaching. The next requirements for a good speaker are a good expressive face, no ugly expression on the face, no awkward gesture, no thumping of tables but a standing posture of dignity and grace.
The physical appearance and gestures of the public speaker are very important because the members of the audience have too see as well as hear the speaker. It is the temptation of most speakers to rely on physical gestures to make a point. A successful public speaker's main object is always to rouse and retain the attention of his audience. It is not easy, but it comes with practice. Humour is a powerful tool. To make the audience laugh is the way to their hearts.
The language of your speech is important. If you speak in English, you must use correct modern English and not use bombastic language. You must be understood by your audience easily and well.
As a conclusion, to become a world class speaker we should practice from the basic requirement/skill to overcome the weakness of fear in front of the audience. So you must do your best by preparing yourself to convince the audience or make them realize that we are a good speaker.
