Bubble Chart is easy to understand : it is a chart describing data using bubbles / circle. The radius of the bubble – circle usually reperesents the measurement of the value of data.
As a rule of thumb : the smaller the bubble – circle radius, the lesser the data value, the greater the bubble, the larger the value.
This visualization is describing the Growth Domestic Products of various nations around the globe.
Update (Monday, 9/18/2017) : Now with sort function! Just try the ‘Sort’ checkbox! 😛 (Note : there seems to be a minor bug here at the blog version, while it works just fine in the Fullwidth view version. Hopefully can fix this soon….