Joy-IT RS232 Shield and RS232 voltage levels First of all, sorry if this is a dumb question, but I'm pretty new to the whole Serial RS232 concepts.
I do have an Arduino Board that, from what I read about, is not able to communicate via RS232 because of different levels.
My question now is: If the Joy-IT RS232 Shield will make up for that. So is this shield handling the RS232 level shift? I don't really know what to look for so I am asking here.
Thanks!
Yes, that shield will handle the level shifting for you. If you look closely at the images of the shield, you see the MAX232 chip, which is a commonly used chip for getting UART (which is the Serial interface of the Arduino) to speak over RS232.
And yes, RS232 uses different voltage levels. The UART on a microcontroller usually uses the voltages 0V and 5V (or 3.3V depending on  it's supply voltage), which is also called TTL levels (Transistor-Transistor Logic), while RS232 mostly works with +-10V (though different voltages are also inside the standard). You see, that this is a symmetrical voltage around ground (0V).