Presentation skills involve effectively communicating information to an audience through speech. There are three main purposes of presentations: to inform, persuade, or build good will. Presentations can be categorized as informative, analytical, persuasive, instructional, arousing, or for decision making. It is important to understand the audience being presented to, as they can be captives, pragmatists, socially motivated, or committed. Using visual aids makes presentations more effective by reducing meeting times, and making presenters seem more professional and credible to audiences.