help please

when I ask for chord (on this site) it gives me a positioan, but! there is allways a yello circle with the R in. what does it mean?

As stated in a post before, R means the root of the chord. Ex. G major has a root on the 6th string, 3rd fret, on the 3rd string, open, and on the frist sring, 3rd fret.