In order to engage with your audience and deliver a memorable presentation, how you introduce the topic and yourself is important. How you conclude and close, is, critical.
The introduction should grab their attention; spell out what is in it for them to listen to you and what you would like them to do as a result. The audience would also like some reassurance that they are in safe hands, you are the credible speaker on this particular subject and will not be dull. And then, with a flourishing linking statement, you may embark on the main body of your material.
Your conclusion should be succinct but not rushed. You want to encapsulate your presentation like a package that they can take home with them. Remind them of the problem or opportunity, restate key points, distilling your message and be bold enough to request action. If there is time for handling questions, prepare a final closing statement. It is so important that the audience remember what you said, not the last question from the audience. For a sense of polish, not only should your close re-state your conclusion but it could also echo some of the words or ideas of your introduction.