When you use sources in your research paper you will need to cite them.
The main purpose of citation is so that anyone reading your research, specifically your instructor, can find the sources you used. Your instructors evaluate the sources you used to see if they are college level and appropriate for your assignment.
There are several styles of citation, and even though they may require the same basic information, different fields of study use different styles. Your instructor will let you know which citation style they want you to use.