A Primary Source is a source that provides direct information. Information you get from a witness would be information you got from a primary source. Information you got from a friend of the witness would not be so.
Examples of a Primary Source
-archives and manuscript material.
-photographs, audio recordings, video recordings, films.
-journals, letters and diaries.
A secondary source is a source that provides information that isn't directly from the event / topic of researching. For example, a friend who was told about the topic is a secondary source of information since they aren't a first hand witness