How Clemson defines plagiarism
A citation is a string of text, usually in two parts, that refers the reader of a paper back to the source of information. The two parts are usually broken up into:
The inline citation
The inline citation occurs in the main body of the text, and is a short reference to the source. Examples:
Previous research has found that the inclusion of relevant citations lends credence to the arguments of papers (Doe, 2000)
Smith's research shows that new data analysis tools have a high degree of success finding occurrences of plagiarism in student assignments 
Here you see that the citations are short, and don't interrupt the flow of reading
The end text citation
The end text citation is a full reference to the original cited work, which allows the reader to locate and use the resource for themselves. Examples:
Doe, John (2000). Why you should cite things. Journal of citing things, 14(7), 134-137. Web link.
 Smith, John. I wrote a book. Clemson, SC: A book publisher. 2004. Print
Here, the full citations include all the information for where, when, and who published the resource. Also, the citation style determines how information is presented for both the in text and end text citations, so make sure you follow citation style guidelines!