It's common for new manga fans to confuse doujinshi with manga. Actually, there isn't a lot of difference since the content, art, and material are essentially the same. There are even some anime based on doujinshi. However, doujinshi — often shortened to "dj" or "doujin" — are actually self-published works that often tend to be more queer-friendly projects.
Source：https://www.cbr.com/best-doujinshi-myanimelist/
