A Speech is the process of expressing one's thoughts and emotions by spoken sounds and gesture, generally done before an audience and for a particular purpose. Source: adapted from Dictionary.com (June 16, 2016). A speech will typically have an opening, a body and a conclusion, according to The Icebreaker, project #1 in the Competent Communication manual.
Giving speeches is a key part of Toastmasters, and yet it is important to note that the Toastmasters International Mission does not refer to speech, but rather to effective communication, so the focus is clearly broader than only giving speeches.
Speeches can include a wide variety of types. There are humorous speeches, dramatic speeches, Tall Tales, Toasts, Roasts, Eulogies and many others. Spoken forms not usually thought of as speeches may indeed be speeches: Evaluations and Elevator Speeches are in this category.