Tag Cloud, also referred to as Word Cloud or Weighted List Chart, is a chart type that helps visualize text data and mostly serves the purpose of conducting the word-frequency analysis across tags, keywords, and so on.
A Tag Cloud can nicely indicate how often each word is mentioned in a certain text body by means of using different colors and sizes for different levels of relative prominence.
In 1990s, Tag Clouds were widely used as a navigation tool on various information resources such as blogs and small portals, helping highlight the most popular tags featuring quick access links. After becoming immensely popular, this solution evolved into a dedicated type of data visualization.
Nowadays, the Tag Cloud chart type is widespread not only in data visualization, but also in infographics.