Estimators are statistical tools or methods used to infer the value of a population parameter based on sample data. They help researchers and analysts make educated guesses about characteristics, such as the average height of a group, without needing to measure every individual. Common types of estimators include point estimators, which provide a single value, and interval estimators, which offer a range of values. In statistics, estimators are evaluated based on their properties, such as bias and efficiency. A good estimator should be unbiased, meaning it accurately reflects the true parameter on average, and efficient, meaning it has the smallest possible variance among all unbiased estimators.