Question

What is the difference between primary sources and secondary sources?

Answer 1

Primary sources are things that come from persons directly involved in the events or lives being studied.  So, let's say World War II is our subject.  Any diary entries or letters (like the diary of Anne Frank or a letter by a soldier) would count as primary sources.  So would any official proclamations or letters or government documents -- such as the Constitution of France or a declaration of war by US Congress.

Secondary sources are written by historians or others after their study of primary sources.

Answer 2

Primary sources are first-hand accounts of a topic while secondary sources are any account of something that is not a primary source. Published research, newspaper articles, and other media are typical secondary sources. Secondary sources can, however, cite both primary sources and secondary sources.
  Hope this helps :) :)