Improvisation and impromptu: common and different

Improvisation is an unprepared speech or a speech created in the process of speaking. But in order to learn to improvise, one must first master the skills of oratory. We can improvise only when we already know how to perform. An unprepared speech is a prepared failure. A person can improvise only when he knows the subject well. That is, improvisation is possible and good when it is prepared by previous experience and knowledge. In order to speak without preparation, you first need to master the basic techniques of public speaking. And add knowledge and experience.