Hello, Can any one explain these two statements for me about algorithms

The first one is:-

"The non-ambiguity requirement for each step of an algorithm cannot be com- promised"

as we know the algorithms is unambiguous steps, but this statement conflict what we know

The second one is:-

"The range of inputs for which an algorithm works has to be specified carefully"

what is the meaning of range? is it the inputs? , could please give me example?