Point estimation uses sample data to calculate a single value as an estimate of an unknown population parameter. A point
estimator is a statistic 
, while its observed value is a point estimate.
For example, the sample mean is a point estimator
of a population expectation
value.
Properties used to compare point estimators include unbiased estimator, consistency, and mean square error. Unlike interval estimation, point estimation by itself does not provide an interval quantifying the sampling uncertainty.
