apples and oranges 是“两码事儿”的意思

When we use the phrase “apples and oranges”, we mean that two things are very different and cannot be compared to each other.

So for example: what is better -- living in the city or living in the countryside? Well, that’s like comparing apples and oranges.
比如：哪个更好——住在城市还是农村呢？其实没法比较的，萝卜青菜各有所爱