I saw this chart on the BBC today:
I would like to create a similar chart, but i do not know what the chart is called to learn how to build this in R.
They are called Sankey Diagrams.
There are a few different options to create these in R. Your example could have been created with straight lines using parallel sets. There are a few other R packages though that can make more complicated diagrams, see this SO Q/A for some examples.