Which is a secondary sources

A secondary source is a source about an event that was produced after the time period. In other words, the person who wrote the secondary source wasn't around to experience the time that he/she is writing about.

Definition of secondary sources: If u mean what is a secondary sources then it is a document or a commentary that quotes or references a primary source, without first hand knowledge of the activity or event.

Things that are secondary source: such as a painting by Mrs Haase about World War 1.