It is important to cite any ideas, opinions, facts, statistics, graphs, images, data, written or spoken quotations or other pieces of information that are not your own. If you use another person’s work and do not cite it you are plagiarizing their work. Penalties can range from having to redo the assignment to getting a failing grade. Learn how to cite!
There are many different styles of citation. Use the style your teacher has requested for your course assignment.
If you want to understand citation styles more thoroughly check out this video.