What is Visualization?

The English word visual originates from the latin word ‘video, videre, visi’ which directly translates ‘to see or to watch’ and data visualization is an extension of this meaning. The display of information in a graphical and tabular format is known as data visualization. It involves the conversion of data into a visual format so that the characteristics of data and the relationship among data items can be analyzed and reported. 
One of the most important senses is that of sight and we unconsciously use it to extract vital information daily. Political polls, stock market pricing, weather forecast, nutritional facts are just a few of the everyday information that is processed through visual means.

Why Visualization?

Two of the main motivations for the use of visualization techniques in data mining are:

Quick absorption of data: The main motivation of Data visualization is that it allows us to quickly absorb large amount of data and find patterns in it. For instance, if I were to give you a data set with over a thousand entries detailing the average temperature in Alaska over the last 2000 years would a table or a graph help you reach a faster conclusion on the effect on time on the temperature?

Application of Domain Knowledge: Data visualization also aids us in our ability to use domain knowledge. A domain specialist can examine visualizations and be able to help determine the best way to finding patterns of interest, because they are able to quickly eliminate many trivial patterns and focus on patterns of interest.