Documentation stands for the process of acknowledging the source we cited for our research paper. In other words, documenting a paper means to tell the reader exactly where we found the information. To let the reader know that we have carefully researched our ideas, to tell the reader about the original source that we have cited and to avoid plagiarism are the main reasons to document sources.
Our ideas can be strong enough to believe by readers only if we carefully researched it. Any stimulus can excite us by our immediate thought, but the reality might be the difference. So, we need to perform many types of research before we decided to include it in our research paper. It would be better to do as much research as possible for the effectiveness of our ideas. And documentation let the reader know that we have carefully researched our ideas.
It is important to let the reader know about the original source we used for our topic in the research paper. It is obvious that if the reader gets interested in our topic, she can be interested to learn more about it. So, while documenting our evidence, we must provide the details of the original source.

In addition, the documentation can be done in two ways, one within the text of the paper which is called in-text citation, and another is at the end of the paper in a reference list. A citation includes three major pieces of information and they are the name of the author, the year of the source, and the page number which is required only for the quotation in the writing. The citation usually occurs in one of two places: within the sentence or at the end of the sentence.
In a nutshell, documentation is important to let the reader know that we have carefully researched our ideas, to tell the reader about the original source that we have cited and to avoid plagiarism