Informative (or informational) and persuasive speaking are related, but distinct, types of speeches. The difference between the two lies in the speaker's end goal and what the speaker wants the audience to leave with.
Informative speeches are probably the most prevalent variety of speech. The goal is always to supply information and facts to the audience. This information can come in the form of statistics, facts, or other forms of evidence. Informational speeches do not tell people what to do with the information; their goal is for the audience to have and understand the information. Academic lectures are often informational speeches, because the professor is attempting to present facts so the students can understand them.
Walter Cronkite
Journalists, like Walter Cronkite, generally use informational speeches to inform their viewers of news events.
Informational speeches may have a tendency to become overdrawn and boring. Their goal is not to excite the audience members, but rather to provide them with knowledge they did not have before the speech.
Like informational speeches, persuasive speeches use information. However, persuasive speeches are designed for the audience to not only hear and understand the information, but to use it to be convinced of a viewpoint. The end goal of a persuasive speech is not for the audience to have information, but rather for them to have a certain view. Persuasive speeches may use some of the same techniques as informational speeches, but can also use emotions to convince the audience. A sales pitch is one example of a persuasive speech.
A common cry against certain persuasive speeches is that they rely too much on emotion and not enough on facts. A persuasive speech that succeeds in convincing the audience to accept a view but is based on faulty or misleading information is unethical.