For the learned and the unlettered alike in our country the Ramayana and the Mahabharata have for centuries been like their two eyes, pointing to them the path of dharma. The two poetic works are not included among the Puranas and are accorded a special place as "itihasas".
"Pura " means "in the past". That which gives an account of what happened in the past is a "Purana", even though it may contain predictions about the future also. The term can also mean what was composed in the past. The genre called "novel" written in prose came after a long period in literature dominated by poetry and drama. When the novel was introduced into India it came to be called "navinam". If "navinam" means new, purana means old.
A Purana must have five characteristic features - (laksanas). The first is "sarga" (creation of the cosmos); the second is "prati-sarga" (how eon after eon it expanded); the third is "vamsa" (the lineage of living creatures beginning with the childrern of brahma); the fourth is Manvantara (dealing with the ages of the 14 Manus, forefathers of mankind during the 1, 000 caturyugas); and the fifth is "vamsanucarita" (genealogy of rulers of the nation including the solar and lunar dynasties). Besides there are descriptions of the earth, the heavens the different worlds.
"Itihasam"="iti-ha-sam" (it has happened thus ). The "ha" in the middle means "without doubt", "truly". So an itihasa means a true story, also a contemporarary account. Valmiki composed the Ramayana during the lifetime of Rama. Vyasa, author of the Mahabharata, lived during the time of the five Pandavas and was witness to the events narrated by him in his epic.
In the Puranas Vyasa has dealt with the stories or events of the past which of course is in keeping with their name (that is " Puranas"). But how? Vyasa could see into the past as he could into the future. So what he has written of the past must be an eyewittness account. However, his contemporaries would not have known about them. The Mahabharata and Ramayana are different. When these works were first made known to the world most people must have been familiar with the characters and events described in them. There is thus no reason to doubt their authenticity. The "ha" in" itihasa"confirms this.
The word "itihasa" can also mean "thus speak they" (that is "great men say that it must be so").
"Aitihya" is not an account of what is directly witnessed: it is to be accepted as a matter of faith. It is also derived from "iti" (thus great men have spoken "). What we actually observe is "this"; what is told by others is "thus".
For a general background, please see here