All "real world" here means is that the program's semantics are correct given empirical conditions. Here, since "data" just means columns which are measures of

All "real world" here means is that the program's semantics are correct given empirical conditions. Here, since "data" just means columns which are measures of the world, the program is modelling a real-world process. Contrast that with algorithms whose semantics are abstract and are correct given essentially mathematical laws, rather than empirical conditions.