CPS, Cambridge Public Speakers, is a certification to award those who excels in communications and public speaking.

 What is public Speaking
 In public speaking, as in any form of communication, there are five basic elements, often expressed as "who is saying what to whom using what medium with what effects?" The purpose of public speaking can range from simply transmitting information, to motivating people to act, to simply telling a story. Good orators should be able to change the emotions of their listeners, not just inform them. Public speaking can also be considered a discourse community. Interpersonal communication and public speaking have several components that embrace such things as motivational speaking, leadership/personal development, business, customer service, large group communication, and mass communication. Public speaking can be a powerful tool to use for purposes such as motivation, influence, persuasion, informing, translation, or simply ethos.
In current times, public speaking for business and commercial events is often done by professionals, with speakers contracted either independently, through representation by a speakers bureau paid on commission of 25-30%,or via other means.
The objectives of a public speaker's presentation can range from simply transmitting information, to motivating people to act, to simply telling a story. Professional public speakers often engage in ongoing training and education to refine their craft. This may include seeking guidance to improve their speaking skills—such as learning better storytelling techniques, for example, or learning how to effectively use humor as a communication tool—as well as continuous research in their topic area of focus.
People who speak publicly in a professional capacity are paid a speaking fee. Professional public speakers may include ex-politicians, sports stars and other public figures. In the case of high-profile personalities, the sum can be extraordinary.
The common fear of public speaking is called glossophobia (or, informally, "stage fright"), although many people simply confuse normal nerves and anxiety with a genuine phobia.
Public speaking and oration are sometimes considered some of the most importantly valued skills that an individual can possess. This skill can be used for almost anything. Most great speakers have a natural ability to display the skills and effectiveness that can help to engage and move an audience for whatever purpose. Language and rhetoric use are among two of the most important aspects of public speaking and interpersonal communication. Having knowledge and understanding of the use and purpose of communication can help to make a more effective speaker communicate their message in an effectual way.
'The soul of delivery is in the manful assertion of the orator's personality, in the revelation of the high purpose by which he is actuated, in the profound conviction of the truth of his course, in the firm resolve to establish it, in the dauntless spirit that faces all obstacles, and, conquering them, sweeps onward to the desired goal.'
Leaders such as Martin Luther King, Jr., Winston Churchill are notable examples of effective orators who used oratory to have a significant impact on society. The speeches of politicians are often widely analyzed by both their supporters and detractors.
Some of the greatest examples of public speaking are well known and studied years after the speech was delivered. Examples are Pericles' funeral oration in 427 B.C.E. over the dead of the Peloponnesian War; Abraham Lincoln's Gettysburg Address in 1863, soon after Sojourner Truth's identification of racial problem in "Ain't I a Woman?" and Mahatma Gandhi's message of nonviolent resistance in India, inspiring Martin Luther King, Jr.'s "I Have a Dream" speech at the Washington Monument in 1963.
Eloquence (from Latin eloquentia) is fluent, forcible, elegant or persuasive speaking. It is primarily the power of expressing strong emotions in striking and appropriate language, thereby producing conviction or persuasion. The term is also used for writing in a fluent style.
The concept of eloquence dates to the ancient Greeks, Calliope, (one of the nine daughters of Zeus and Mnemosyne) being the Muse of epic poetry and eloquence.
"The Effects of Trim's Eloquence". George Cruikshank's illustration to Laurence Sterne'sThe Life and Opinions of Tristram Shandy, Gentleman
Eloquence derives from the Latin roots: ē (a shortened form of the preposition ex), meaning "out (of)," and loqui, adeponent verb meaning "to speak." Thus, being eloquent is having the ability to project words fluidly out of the mouth and the ability to understand and command the language in such a way that one employs a graceful style coupled with the power of persuasion, or just being extremely graceful in the interpretation of communication.
Petrarch (Fracesco Petrarca), in his study program of the antiquity (Italian Renaissance) focused attention on language and communication. After mastering language, the goal was to reach a “level of eloquence”, to be able to present gracefully, combine thought and reason in a powerful way, so as to persuade others to a point of view. Petrarch encouraged students to imitate the ancient writers, from a language perspective, combining clear and correct speech with moral thought. The Renaissance humanists focused on the correlation of speech and political principles as a powerful tool to present and persuade others to particular concepts. At the core of presentations was the use of graceful style, clear concise grammar and usage, and over time the insertion of rational and emotional arguments.
In modern times, colloquial speech entered into presentation styles deemed eloquent.
Eloquence is both a natural talent and improved by knowledge of language, study of a specific subject to be addressed, philosophy, rationale and ability to form a persuasive set of tenets within a presentation.
"True eloquence," Oliver Goldsmith says, "Does not consist ... in saying great things in a sublime style, but in a simple style; for there is, properly speaking, no such thing as a sublime style, the sublimity lies only in the things; and when they are not so, the language may be turgid, affected, metaphorical, but not affecting." (Of Eloquence, 1759)
Reference: Wikipedia