Infographics are "graphic visual representations of information, data or knowledge intended to present information quickly and clearly." (Wikipedia).
Infographics include a lot of things, from individual charts, plots, and maps to presentations that combine these data visualizations with additional visuals and language to tell a story.
(Image source: http://r13hybrarian.weebly.com/infographicstla.html)
Remember these guidelines:
Here's a selection of very important functions in Powerpoint for designing posters and infographics.