A reference list lists only the sources you refer to in your writing.
A reference list appears on a new page after the end of a paper. It is arranged alphabetically, and references use hanging indentation (first line flush left, second and subsequent lines of a reference are indented in).
The purpose of the reference list is to allow your sources to be be found by your reader. It also gives credit to authors you have consulted for their ideas. All references cited in the text must appear in the reference list, except for personal communications (such as conversations or emails) which cannot be retrieved.
A bibliography is different from a reference list as it lists all the sources used during your research and background reading, not just the ones you refer to in your writing.
For further information see the APA Manual p. 281–309.