Yeah, Chine is litterally called "Middle Country" (中国, ちゅうごく), as inside/in the middle are both meanings of 中, albeit with a direrent pronunciation
中 is "inside" or "middle/center" in a more physical sense (e.g. talking about locations or objects). 内 is also "inside", but just for a house or building, and is often used in a more abstract context (e.g. talking about things relevant to yourself/your family/company etc).
Please find a way to distinguish when you want 内 or 中 to be translated from English. I don't appreciate being marked incorrect when writing 内 as meaning inside, as this is actually true.