1、 Ambiguity and uncertainty are intrinsic parts of our existence and learning to grapple with undefined aspects is vital, not just in the computational and mathematical realms, but in life at large. When a function does not have a correct output or when a variable has not been assigned a specific value, it achieves the status of undefined， In both fields, the undefined concept is a marker, a placeholder, signaling that a value or answer should exist, but doesn't presently, due to one reason or the other. For instance, in JavaScript, a well-known high-level programming language, an undefined property implies that the object lacks the given property or that property has yet to be assigned a value， In Mathematics, undefined could mean the result of dividing any number by zero, a scenario that goes against the fundamental principles of Arithmetic.
2、 It's like an abyss, an ambiguity, a void, a question that refrains from giving a clear answer， Profoundly, the existence of 'undefined' teaches us that not every question has an answer, not every problem has a solution, and that's perfectly acceptable.In computer programming and mathematics, the term "undefined" plays an often-overlooked yet immensely significant role， Nevertheless, undefined is not to be confused with 'null' or 'NaN' (Not a Number), as the latter two hold meanings distinct from undefined; 'null' refers to no value or no object while 'NaN' refers to a value that is not a recognizable number.
