Returns a list. If anything1 and anything2 are lists, it concatenates the two lists (combines their items into one list). If anything1 is a list and anything2 is not, it puts anything2 at the end of the first list. If anything1 is not a list and anything2 is a list, it puts anything1 at the front of the second list. If both anything1 and arg2 are not lists, it creates a new list containing both anything1 and anything2.