In version 20.10, 20.10, and 21.4, there are 2 types developer license : RPA developer license and RPA developer Pro license which is for Pro profile(C# support, test function etc).
In 21.10, Studio profile and Studio Pro profile are unified to Studio profile. So there is no difference in the latest version. However, RPA developer might be discontinued in the future because it’s not defined in license model page, i think.
As per my experience please find the below difference for RPA developer vs Automation developer license.
Both are developer licenses we can assign to the developer for their development activities.
But these two licenses have difference
The main difference is Automation developer license will enable studio pro profile capability
Like Test manager, mobile automation etc. But RPA developer license cannot have access to studio pro capabilities. Please note that for latest version of studio uipath combined both studio and studio pro profiles but the activites or capabilities related to studio pro will come only with automation developer.
And also automation developer license is preferably use for attended bot.
I hope you will get some idea on these two licenses. If you have any more doubts please reach out to UiPath for more details.