Generic functions are functions that serve a generic purpose. They usually accept a function pointer as an argument to specify what exact operation to do with the data they operate on.
Most languages provide you with some generic functions, and C is no exception.
Examples
One such example is the qsort function:
void qsort(void *base, size_t nel, size_t width, int (*compare))Which, as you can probably tell from the name, is the quicksort algorithm.
There are many more, but in the context of CPSC 213 you won’t have to memorize any, you just need to know how to use them. This generally involves just passing a pointer function of the correct form to the generic function in question.