What is the meaning of Standard Normal Distribution or Standardized Normal Distribution?

Occurs when the underlying normal distribution is converted by changing its scale. The importance of this is that different normal distributions can now be compared to one another. Otherwise, separate tables of values would have to be generated for each pairing of mean and standard deviation values. This standardized variate term is often expressed as Z is N(0, 1), or Z is a normal distribution with a mean value of zero and variance equal to one.