What is Estimation? | Define Estimation

This video describes basic definitions of Estimation
Basically estimation is the process of approximation to find a usable value for some specific purpose.
Estimation also makes a rough calculation for any number, data, and quantity to make it easier to find the answer which is close to actual answer.
Estimation is a method to finding best information even if the input data is uncertain or uncompleted.

Estimation is a process of judging or roughly calculating a number or a value to express the approximated result.
Estimation is generally performed by sampling process.

In project management the estimation is the process of predicting cost, time and other required resources to complete a project by carefully analyzing the available data.