The websites visited visualization shows the number of visits to a website (visits option), or the number of different days a site was visited (habits option) as the circle size. This gives you a broad view of how much you use various websites. Hovering over the circle shows the name of the website, the number of visits, and the category the site belongs to (e.g. email, social media, etc.). Switching from habits to visits (and vice versa) shows the circles transition from one layout to the other.
A visit can be to the same url (e.g. the New York Times home page 17 different times) or to different pages within that site (e.g. 17 different New York Times articles). You could find out “where did my time go when I was online yesterday?” or “how has my focus shifted over the past months?”. Visit counts give an indication of time spent on a site. The habits view tends to be more stable over time, while the visits view can change more rapidly when one site is visited intensively.
The visualization lets you highlight a circle and the highlighting remains as you change the time scale and the view (e.g. switch from habits to visits view). This highlighting can help you understand your use of a particular site.