What are a primary source and a secondary source?

Answer if this question concerns literature, not electricity.

Primary Source: This is your main source, a source that was recorded when the event happened.

Secondary Source: A source based on other sources e.g. a book about the event or a biography written by person A about person B.

(An autobiography is an example of a primary source because someone wrote it about his or her own life. )

 

Answer if this question concerns electricity, not literature.

Primary Source: A non-rechargeable chemical battery which can produce a useful output current when a load is applied to it. It does not store electric charge and it cannot be re-charged when its supply of electric current has been used up.

Secondary Source: A rechargeable chemical battery which can produce a useful output current when a load is applied to it. It stores electric charge and can be re-charged when its supply of electric current has been used up.