Each and every time information is taken from a source (whether it is taken as an exact quote, re-worded, or paraphrased) and used in a research project, credit must be given to the original source of information. Typically, that is done in two ways:
Most research projects require both in-text citations and a list of works cited at the end of the project.
Check with your instructor to determine which style is required for your research project. The handouts linked here provide examples for documenting the most commonly used types of resources. (You will need Adobe Reader to view or print the first four PDF documents below):