Circle, Pie Chart and SunBurst are all circle based glyphs that allow to represent a different number of dimensions such as the dataset from which the datapoint is taken, or its category.
Glyphs either use data from a specific country or a group of country, which is called cluster.
Each glyph may contain temporal information through the display of a stacked area chart in the middle of the glyph.
Every glyph has a unique name that can be created through the use of these 3 features.
For example the glyph C-Co-1 is a circle (C) that takes information from a country (Co) and displays temporal information (1).