Many beginners have a notion that programming an Arduino makes them embedded engineers. But real skills start much deeper.
Arduino is a network for open-source electronics focused on a technology that is easy to use. By giving a list of instructions to the microcontroller on the board, you can tell your board what to do.
When it comes to performance, there's a world of difference between the Raspberry Pi and Arduino. The former, after all, is technically a fully functional computer that can run games, word processors, ...