the value of a sample statistic that is used to estimate a population parameter
Note: this term means using the situation of a point to estimate the one of the whole.
eg: In a research, population involves 500 people, of them 50 are choosed as the sample, the average age(a mean) of the sample people is 60, then we can estimate the average age of the whole population is about 60, maybe 62, thereafter we assume 62 as the population average age. This number 60 is called the point estimate, 62 is called an estimate . Such an procedure is called estimation or point estimation .