Data visualization refers to any way of presenting information so that it can be interpreted visually. This is a pretty broad bucket that can include things like charts or graphs, diagrams, images, animations, and infographics. Data visualization makes use of our ability to recognize trends, patterns and relationships to draw out meaning from our data. This can be useful in analyzing your data (yes, data visualization can be an important activity in data analysis!), or in communicating the results of your work to others.
Data visualizations can can help readers comprehend complex information quickly, identify relationships and betters, and take what may be considered bland information, and transform it into a story.