Tell me what are these visual charts appropriate for? 

Choropleth map, heatmap, scatter plot
Density plot, horizon chart, line chart,  Geographic heatmap , Bar chart
Although any of these charts might be used for various purposes, here is a list of use cases and corresponding chart types;

Comparison: Bar chart, line chart
Correlation: heatmap, scatter plot
Distribution: Density plot, horizon chart
Geospatial: Choropleth map,  Geographic heatmap