A large non-standardized web image designed by those who have little to no knowledge or concern for web design and/or accessibility standards. A form of web pollution; infographics are simply flat images which by nature contain no searchable text, links or content than can be indexed by search engines and thus found by people. Since these flat images are devoid of any relevant text, they are also inaccessible by word readers for the visually impaired.
Here, check out this infographic I've designed in photoshop. It's only an image of course, so you can't highlight any text, or click any links, and if you use a word reader just your s**t out of luck; but hey it looks cool and it was easy to make, so it's winning.
A pretentious graph
Ed: Check out this infographic on crime rates
Stan: That's a pie chart