Episodic Memory and Semantic memory are the two types of long term memory that falls under declarative memory.
Episodic Memory is can be explained in simple terms as
the ability to remember or recall events happened in the past and specifically the when and where.That is this helps to remember certain things like certain situations or events and also some past experiences. Not all human beings have the ability of recall the past events.
Research say episodic memory grows or develops to full at only about four years of age. This episodic memory plays a vital role in shaping up ones identity. This memory is the first one to fade off when one is experiencing Alzheimer's or any other neurodegenerative mind disorders. Remembering first gift from your boyfriend, first day in college etc are examples of episodic memory.
Semantic Memory is the memory associated with meanings and concepts and not is not related to personal experiences. This is knowledge based and purely independent. Another division of memory is procedural memory along with declarative memory.
A simple example is while reading a book or article, the procedural memory is the one which is connected with how to read the article or book and the semantic memory is associated with understanding the meaning of words as well as how the words are linked to each other. Semantic memory is more structured.
Factual Memory is the connected with remembering.This can be best explained with an example. A boy along with his parents eye witnessed the burning of a theater. Twenty years passed and the boy no longer remembers that incident and his parents reminded him of that. And after some ten years the boy now a grownup will remember this incident on the basis told by his parents and not would not be true that he personally remembered it.