Research is, in effect, building on the ideas of others. It helps you grow as a researcher to acknowledge what other researchers have contributed. By learning from others, you can be more informed, and it fosters academic collegiality where you get to be part of the conversation. Citing the sources that you use is an important part of academia and being a professional in your field.
Also, including citations helps others find the resources you've used. It helps the readers understand the construct of your thinking. It upholds academic integrity, which is part of the Colorado Mesa University Maverick Guide.
Not including citations for your work could lead to plagiarism which could result in a failing grade for the assignment or course or even expulsion. Citing your sources is important, but it's equally important to know which style to follow when creating in-text citations as well as those at the end of your research.
There are many styles of citation, but three are most commonly used: APA (American Psychological Association), MLA (Modern Language Association) and Chicago (sometimes referred to as Turabian). Different disciplines follow different styles. APA is mostly used by the social sciences (Education, Psychology, History, Sciences); MLA is mostly used by the humanities (Linguistics, English, Cultural Communications); Chicago is mostly used by Business, History, and Fine Arts. However, it is always best to consult with your instructor, who is your main audience when writing or presenting, and follow what they would like you to use.