what does the degrees of freedom refer to in the student-t distribution
Student's t-distribution If we take a sample of n observations from a normal distribution, then the t-distribution with   ν = n − 1  {\displaystyle \nu =n-1}  degrees of freedom can be defined as the distribution of the location of the sample mean relative to the true mean, divided by the sample standard deviation, after multiplying by the standardizing term    n   {\displaystyle {\sqrt {n}}} . In this way, the t-distribution can be used to construct a confidence interval for the true mean.