You have ever heard your teacher say these words: ‘Now children, I am giving you a test on reading comprehension’? What does that mean? If you look it up in a dictionary you will find that the meaning of COMPREHENSION is: capacity of the mind to perceive and understand; power to grasp ideas; ability to know.
When the teacher announced the test, your thoughts went to the earlier classes and you started remembering all that was taught. Even before that you understood that ‘test’ meant some kind of a process by which the teacher tries to know how much you have learnt. Again, by ‘reading comprehension’ you understood that the teacher is going to give a test which would include a written text and you would be required to answer questions on your understanding of the text. Here, the test is on what you have studied earlier to see if you have understood the lessons that the teacher taught you. However, once you are out of school and your text books then you are on your own!