The difference between non-academic and academic writing can be important to you when you are doing research for a paper. It also will concern you if you are considering writing as a career.
When you are writing a research paper that requires sources, you will want to use material that falls under the category of academic writing. These sources will be written by experts in their fields, and in many cases they must go through a peer review process where other experts read and approve the work before it gets published. The articles will be published in scholarly journals that reach other professionals rather than in magazines or newspapers read by lay people. Scholarly journals include sources such as the New England Journal of Medicine and the Journal of Applied Psychology. The language of such articles is very formal, and an extensive list of references will be included. The authors' names will be given along with their credentials.
Non-academic writing is written for a lay audience. It includes newspapers, magazines, and books that you would find at a brick-and-mortar bookstore such as Barnes and Noble. It also includes blogs and websites. Such writing will be informal, possibly even colloquial. The author's name may not be given, or if it is, there may be no indications of the credentials the author has. Often, the author is not an expert in a field but has interviewed people who are. When using non-academic writing in your research paper, you must be diligent to ensure its credibility. Many informational websites, including Wikipedia, can be edited by users, so you have no guarantee that the last person who edited the article was knowledgeable about the subject.
Pay attention to the requirements for your assignment. You may be required to use only academic sources or to have a certain number of academic sources in your paper. Whether your instructor specifies it or not, don't use sources such as Wikipedia that can be altered by users.
Finally, if you are considering writing as a career, you should consider whether you want to pursue academic or non-academic writing. Academic writers are experts in their fields first, and writers second. As a non-academic writer, you could pursue writing fiction or non-fiction books or writing for newspapers, magazines, or digital media.