For some people, speaking in public is just something they never want to do. It can be a serious fear for some people, and is referred to as glossophobia. The nervousness that arises from the realization that one has to go speak in front of people can be avoided if one simply masters the art of public speaking, or gets some help getting over the fear. Some people simply need public speaking help.
Ever since ancient Greece, people have been studying and mastering the art of public speaking. It was a sign of education and a way for the community to create a forum through which to communicate with each other. In ancient Greece, however, it is safe to say at least one person had a fear of public speaking. They did not offer such things as public speaking help or communications classes, stuff you can get easily today.
Today, public speaking anxiety is very prevalent, as a lot of people are simply terrified of speaking in public. This is not a real irrational fear, as a lot of people do not like speaking in public. However, most public speaking coaches will agree that you should first be familiar with all the technical aspects of your presentation, so you know everything out of your control will be good.
Public speaking courses teach you to practice your speech or presentation, and agree that it is especially helpful to watch and critique yourself. Furthermore, being masterful of the subject matter is heavily suggested. The better you know the material, the better your public speaking skills will be. You certainly can talk about the things you know.
If you struggle with public speaking, there are a number of different ways to improve. Firstly, you should work on improving your overall confidence. Having good confidence is sort of a prerequisite to good public speaking. Everything else can be learned and tweaked through professional public speaking help.