If a presentation were a painting, then it's background would be a canvas. As any painter worth their palettes will tell you, a lot of thought goes into the selection and curing of a blank canvas. And that's even before the first streak of charcoal or a load of paint touches the very medium.
Presentations are similar - a well designed background can lend immense value to the final product.
Choosing a proper background is a significant job - it can set the ambience for your presentation. Colours, textures and images play an important psychological role that may enhance the creativity and suitability of a story or theme. Backgrounds need to be elegant and subdued - it's purpose is to never distract your audience from an actual event. Simplicity is of paramount value. Easy PowerPoint is a premier presentation tool and Microsoft has added many features which allow you to use backgrounds in myriad ways.