Patañjali's Yogasūtra I.7

I.7 - pratyaksa-anumāna-āgamāḥ pramāṇāni

Correct comprehension arises out of direct observation, inference and reference from reliable testimony. 

The mind can register an object directly through the senses. When the information available is inadequate or incomplete for sensory perception, other faculties such as logic, sampling and memory, aid in a more accurate comprehension of the object to be inferred. When no direct comprehension is possible, reference to reliable sources of testimony, such as written texts or trusted individuals, can enable an accurate understanding of the subject in focus. 

This is how we understand places, people or concepts outside our own direct experiences. Correct comprehension in the state of Yoga is different from comprehension at other times. It is closer to the true nature of the object of understanding.