In NCERT Class 12 Maths Chapter 1, the domain and range of a function describe its input and output values:

• Domain: The set of all possible input values (x) for which the function is defined. Example: For f(x)=1/x, the domain is all real numbers except x=0.
• Range: The set of all possible output values f(x). Example: For f(x)=x² , the range is [0, infinity) because squares are always non-negative.