What is the Difference Between a Speech, a Presentation, a Lecture and a Talk?

Speech, presentation, lecture, talk.

Not only them, but also TED talks, symposiums, seminar, keynote, PhD/master defense, and a few others.

These terms are often used interchangeably, even on this blog. They are not the same though. They have a lot in common, as they are all different forms of public speaking, bu they have a few distinctive features. What are they? In today’s article I will try to answer this question.

Talk as the umbrella term

Speeches, presentations and lectures are different beasts. You will also often read the mention of talks, as in “giving a talk”. On this blog, when I’m using this term, I’m using it as an umbrella term, i.e a talk is any public speaking event, generally speaking. In other words, a talk can be anything, whether it’s a speech, a lecture, a seminar, a presentation, etc.

The speech, a formal or semi-formal event

A speech is usually a formal kind of talk, or at least a semi-formal one. They can go from the very formal, like when the president or the king of a country is talking to his citizens (or even those of other countries), to very little formality, like when everybody (including you) is drunk at your best friend’s wedding ceremony and you are making fun of him during a very clever speech with tons on hilarious anecdotes.

Somewhere in the middle, keynote speeches are somewhat formal talks given by an important person in a domain, usually to open or close a conference.

Speeches are usually not an end in themselves, but are part of an event (like the opening or the ending of a ceremony or a conference).

Speeches tend to be rather short, usually as short as 1 minute and no longer than 15 minutes, although there are obviously exceptions.

Usually the speaker does not use powerpoint slides, as he stays on the surface of the topic he is talking about: a speech’s goal in not to get into the details.

A speaker giving a speech can be reading aloud a pre-written speech (this is the most frequent option), but he can also say it after having memorized it, or can tell on a more conversational tone, from an outline or a list of predefined bullet points.

Some speeches are even completely improvised, although this is usually limited to the least formal events. Some professional speakers can deliver unprepared speeches when they are asked to, during an event, but these speeches tend to be very short.

Another specificity of speeches is that, very often, speeches are not written by the speaker himself, but by a speechwriter. You see, Mr. President has more important things to do than write his own speeches. Which is quite understandable, in my opinion.

So, a speech usually refers to a talk that is:

  • short,

  • usually read aloud or memorized,

  • without powerpoint slides or any other visual element,

  • not detail-oriented,

  • somewhat formal,

  • told by an “important” person,

  • sometimes not written by the speaker himself.

The business presentation, a more technical and detail-oriented talk

Presentations, sometimes called business presentations or powerpoint presentations, are talks given in a professional context, where the speaker is talking to his colleagues, his bosses, his clients, his peers (in the case of scientif presentations for instance) or even his teachers (in the case of students).

They are usually less formal than speeches and are given by less important people in the organization. I mean, while your boss might give a speech at the beginning of a event, you are more likely to give a business or technical presentation, than the opposite (your boss giving the presentation and you giving the speech). Well, unless you are the boss, obviously.

Presentations are usually longer than speeches, and will rarely be shorter than 5 to 10 minutes, and can be as long as an hour, or even longer. PhD defenses are usually 45 minutes long, questions by the jury not included.

Presentations usually involve the use of powerpoint slides. That’s because presentations are more detail-oriented, more technical, and as a saying goes, “a picture is worth a thousand words”. But more often than not, powerpoints are abused, and bore the audience to death. For instance, when the speaker puts way too many words on his slides, like full sentences, and then reads them aloud because he didn’t prepare enough and thought “oh, that’s OK, I’ll just read my slides”. Please don’t do that. Please. Unless you want your audience to be victim of the infamous death by powerpoint.

Powerpoint slideshows can also be very distracting is misused. As the great high-schooler and superhero Peter Parker used to say, “with great power comes great responsibilities”, so please be careful. There’s a lot to be said about this tool, but I’ll keep that for a later post.

Although there are exceptions, presentations are usually delivered with a more conversational tone than speeches, to the point it is usually considered acceptable to interrupt the speaker during a presentation, to ask for clarification. That’s an important difference with speeches: believe me, you don’t want to interrupt your CEO during his speech to ask for more details.

In your professional life (including the years you are a student), the presentation is the kind of talk you are the most likely to give. Unless you become a very important people, that is.

So, a presentation usually refers to a talk that is:

  • a little longer than a speech,

  • focused on details,

  • given by a specialist,

  • usually told from an outline, and very rarely read aloud,

  • written and prepared by the speaker,

  • usually illustrated by a slideshow,

  • usually ends with a session of questions by the audience.

The lecture, the teacher’s talk

The lecture is the kind of talk a teacher will give. They are very close to business presentations, athough here the goal is to educate, to let students learn something new, change their conceptions about a given topic, or understand a hard to grasp concept.

Usually lectures are not memorized but are improvised from an outline, or a list of bullet points, organized in a pedagogical way. Your teacher is usually not reading aloud his paper, or, worse, his powerpoint slides. If he does, I’m so sorry for you.

Unless the lecture is given to a wide audience, it can usually be interrupted by questions, because sometimes students need more explanation on a given point. A good teacher will, sometimes, go as far as reorganize his whole lecture on the fly as he discovers his material is too easy or too difficult for his students.

Yes, teaching is hard and requires a lot of adaptability and flexibility, much more than other kinds of talks. It also requires the speaker to “read” his audience for the whole lecture, and try to guess how much they understood so far.

Lectures are also the only kind of talks young children will encounter in their day-to-day lives. Which does not mean lectures are the only way (or even the best way) to teach something to students, by the way.

So, a lecture tends to be a talk that:

  • is longer than other kinds of talks,

  • tries to teach something,

  • is highly flexible and highly adapted to its audience,

  • usually uses powerpoint slides or other visual elements,

  • can usually be interrupted by questions from the audience.

It’s not an all-or-nothing kind of thing

OK, the definitions above are mine, so feel free to disagree with some of them.

Moreover, there are not well-defined boundaries between all these kinds of talks. Some talks are very hard to classify.

For instance, according to my definitions, TED talks are at the same time:

  • speeches (they are more often than not memorized talks and don’t use slides, and the speaker is not supposed to be interrupted nor will answer questions),

  • lectures (they tend to be educational, by their very nature), and

  • presentations (the typical TED talk is 18 minutes long, which is very short for a lecture, and somewhat long for a speech, and the TED conference is a, well, conference, with several speakers, one after the other).

Another example: seminars are usually both lectures (explaining something to the audience for a rather long time) and presentations (as they are technical and are given to professional rather than students).

Why should I care?

So, why did I mention the differences between them? That’s because I wanted you to be clear with the fact there are tons of very different speaking contexts, and each of them will have a different set of best practices and rules.

Sometimes, trying to memorize your talk will make sense. Sometimes, reading aloud will be better. In even other situations, using a conversational approach from a predefined outline will be better.

It all depends on the context. Not only that, but it also depends on your personality.

So, beware any source giving you hard and fast rules about public speaking. Because such rules don’t exist.