Neyman construction is a frequentist method to construct an interval at a confidence level that if we repeat the experiment many times the interval will contain the true value a fraction of the time.
The probability that the interval contains the true value is called the coverage probability.
A Neyman construction is carried out by performing pseudo-experiments, i.e. constructing data sets corresponding to a given value of the parameter. The pseudo-experiments are fitted with conventional methods, and the space of fitted parameter values constitutes the band of which the confidence interval can be selected from.