Human self-reflection is the capacity of humans to exercise introspection and the willingness to learn more about their fundamental nature, purpose and essence.
A process is a set of interrelated activities that interact to achieve a result.
Estimation is a forecasting process of rough quantification of the quantity of resources we are going to need in order to accomplish a certain activity.
A resource can be: time, money, energy…
A work breakdown structure (WBS) is a document in which the critical work elements, called tasks, of a project are illustrated to portray their relationships to each other and to the project as a whole.