When writing, you'll support your own ideas by referring to the works of other authors. Citing these authors fulfills certain purposes:
Although different styles are used in citing sources, they all provide enough information for someone to find the source being referenced. The parts of a citation in APA format are shown below for several common types of sources. Examples of citation formats for other sources are available here.
Website

Authored Book

Edited Book

Journal Article

In addition to your list of references, you'll also want to cite sources within your text to let your readers know what information is coming from your sources. Format for APA in-text citations follows this format:
One author: (Adeyemi, 2019)
Two authors: (Adeyemi & Wilson, 2019)
Three or more authors: (Adeyemi et al., 2019)
When you refer to information from a source in your text, include the in-text citation right after the relevant information:
40% of the national bigfoot population lives in Colorado (Adeyemi, 2019).
If you mention the author(s) in the sentence, include the date in parentheses after the names:
Adeyemi (2019) found that 40% of the national bigfoot population lives in Colorado.
If you quote directly from the source, include the page number(s) and place quotation marks where appropriate:
"The moon is made out of cheese, but not crackers." (Adeyemi, 2019, p.22).
Adeyemi (2019) found that "the moon is made out of cheese" (pp. 22-23). Crackers do not seem to be part of its composition.